7th Grade - Chapter 3 ONLINE REVEIW
True/False
Indicate whether the statement is true or false.
____ 1. A proton is a positively charged particle present in the nucleus of all atoms.
____ 2. The mass of a proton is much greater than the mass of a neutron.
____ 3. Atoms of the same element can have a different number of neutrons.
____ 4. Dalton believed that the atom was a hard sphere that was the same throughout.
____ 5. J. J. Thomson did experiments that showed that atoms cannot be divided into smaller particles.
____ 6. Rutherford’s experiment showed that alpha particles could pass through foil because most of an atom is neutrally charged.
____ 7. The strong nuclear force can hold the protons of an atom together only if the protons are far apart.
____ 8. Once a living organism dies, the amount of carbon-14 cannot be replaced.
Modified True/False
Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement true.
____ 9. The idea of the atom was first proposed by Dalton. _________________________
____ 10. An element can be identified by the number of protons in its nucleus. _________________________
____ 11. When an atom's atomic number increases during transmutation the atom has emitted a beta particle. _________________________
____ 12. The mass of an electron is about equal to the mass of a proton. _________________________
____ 13. The mass number of an element can be used to determine the number of electrons in an atom. _________________________
____ 14. Half-life is a measure of the rate of decay of an isotope. _________________________
____ 15. The number of electrons in an atom must equal the number of neutrons. _________________________
____ 16. Except for hydrogen-1, the atomic number of an isotope is always greater than the mass number. _________________________
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____ 17. Why were early philosophers’ theories about life considered only theories?
a.
People had other ideas that were more sensible.
b.
Philosophers had no evidence or proof to back up the theories.
c.
Philosophers would not share their proof with the public.
d.
Scientists did not take philosophers seriously.
____ 18. Which is NOT an example of an element?
a.
carbon
b.
gold
c.
silver
d.
sodium chloride
____ 19. Scientists often revise older scientific theories and models to account for new information. Which scientist revised his own hypothesis about the atom to account for the existence of a nucleus and proton?
a.
William Crookes
b.
John Dalton
c.
Ernest Rutherford
d.
J. J. Thompson
____ 20. Which is the most current scientific model of the atom?
a.
alpha particle model
b.
electron as wave model
c.
electron cloud model
d.
Thompson’s atomic model
____ 21. Sonal made a time line of atomic research and discovery.
How many years passed between Rutherford’s first discoveries about the atom and his first atomic model?
a.
10
b.
14
c.
19
d.
35
____ 22. What does an element’s atomic number represent?
a.
the mass of an one atom of an element
b.
the number of isotopes in the nucleus of one of its atoms
c.
the number of neutrons in the nucleus of one of its atoms
d.
the number of protons in the nucleus of one of its atoms
____ 23. Which two numbers do you need to know in order to find the number of neutrons in an isotope?
a.
atomic number and mass number
b.
atomic number and number of protons
c.
mass number and number of electrons
d.
number of protons and number of electrons
____ 24. In which type of atomic nucleus is radioactive decay most likely?
a.
nucleus with the highest mass number
b.
stable nucleus
c.
transmutated nucleus
d.
unstable nucleus with the lowest mass number
____ 25. Why would an element’s atomic number change after transmutation?
a.
It has added an alpha particle.
b.
It has expelled an alpha particle.
c.
It is no longer an isotope.
d.
It has changed into an isotope.
____ 26. Jerry is using a calendar to figure out how long an 8 g sample of iodine-131 will take to decay. It has a half life of 8 days.
If Jerry starts his experiment on March 1, on which day will he have only 1 g of iodine-131 left?
a.
March 9
b.
March 12
c.
March 25
d.
March 31
____ 27. Why would an archaeologist find it useful to know how much of the element carbon-14 is in a fossil?
a.
They can figure out how much uranium is in the fossil.
b.
They can calculate half-lives of other elements in the fossil.
c.
They can use the half life of carbon-14 to calculate when the animal lived.
d.
They can infer the size of the animal when it died.
____ 28. Which of the following is NOT a use of isotopes?
a.
to detect tumors in the body
b.
to diagnose thyroid problems in humans
c.
to store radioactive waste
d.
to tell how plants use phosphorus to grow
____ 29. Why can’t a geologist use carbon dating to find the age of a rock?
a.
Carbon-14 can only be found in things that were once alive.
b.
Carbon-14 has a different half life when found in rock.
c.
Rocks become radioactive after carbon dating.
d.
Rocks erode too quickly to perform the test.
____ 30. If two atoms have the same number of protons but different numbers of neutrons, they will have the same ____.
a.
half-life
c.
atomic number
b.
mass number
d.
degree of stability
____ 31. If an isotope has an atomic number of 25, which of the following is most likely to be its mass number?
a.
25
c.
75
b.
50
d.
100
____ 32. During beta-particle emission, a neutron splits into ____.
a.
a proton and an electron
c.
two electrons
b.
two protons
d.
two neutrons
____ 33. For a radioactive substance, half-life is determined by ____.
a.
the mass of a given sample
b.
the temperature at which the substance is stored
c.
the presence of magnetic fields
d.
none of the above
____ 34. Which particles have almost the same mass?
a.
proton and electron
c.
electron and neutron
b.
proton and neutron
d.
all three particles
____ 35. Which item best represents Dalton’s mental image of an atom?
a.
a cork
c.
a marble
b.
a candy bar with nuts
d.
a balloon full of air
____ 36. Which item best represents Thomson’s mental image of an atom?
a.
a sponge
c.
a bowling ball
b.
a chocolate-chip cookie
d.
a beach ball
____ 37. Based on his experiment, Rutherford concluded that atoms were ____.
a.
dense positively charged particles
b.
uniform throughout
c.
mainly empty space
d.
made of protons, neutrons, and electrons
____ 38. Which type of particle would NOT be deflected by a magnetic field?
a.
beta particle
c.
proton
b.
alpha particle
d.
neutron
____ 39. A transmutation involving the release of alpha particles produces atoms whose atomic number has ____.
a.
decreased by 2
c.
decreased by 1
b.
increased by 2
d.
increased by 1
____ 40. A transmutation involving the release of beta particles produces atoms whose atomic number has ____.
a.
decreased by 2
c.
decreased by 1
b.
increased by 2
d.
increased by 1
____ 41. The fluorescent screen in Rutherford’s experiment was designed to ____.
a.
detect charged particles
c.
deflect charged particles
b.
attract charged particles
d.
repel charged particles
____ 42. The nucleus is held together by ____.
a.
magnetic attraction
c.
atomic glue
b.
gravity
d.
the strong nuclear force
____ 43. A 10-g sample from a healthy 200-year-old redwood would contain ____ carbon-14 as a 10-g sample from a 20-year-old redwood sapling.
a.
one-tenth as much
c.
twice as much
b.
the same amount of
d.
half as much
____ 44. Which of the following properties of iodine-131 make it a good choice as a tracer element?
a.
It is absorbed equally by all cells in the body.
b.
It is absorbed mainly by cells in the thyroid.
c.
It has a relatively long half-life.
d.
It is a normally stable isotope.
____ 45. ____ contain(s) only one kind of atom.
a.
Matter
c.
Chemicals
b.
Elements
d.
Radioactive materials
____ 46. A(n) ____ is the basic unit of matter.
a.
electron
c.
atom
b.
molecule
d.
space
____ 47. Particles in an atom’s nucleus that do not have an electric charge are called ____.
a.
neutrons
c.
ions
b.
electrons
d.
protons
____ 48. The atomic mass of an atom consists of the mass of the ____.
a.
protons and neutrons
c.
neutrons and electrons
b.
protons and electrons
d.
neutrons, protons, and electrons
____ 49. In an atom, the electrons can be found in the ____.
a.
nucleus
c.
isotope
b.
neutron
d.
electron cloud
____ 50. J. J. Thomson used the fact that ____ charges attract each other in his cathode-ray tube experiment.
a.
like
c.
atomic
b.
neutral
d.
opposite
____ 51. The mass number of an isotope is the number of ____.
a.
electrons and protons
c.
neutrons
b.
neutrons and protons
d.
protons
____ 52. Isotopes are atoms of the same element that have a different number of ____.
a.
protons
c.
neutrons
b.
electrons
d.
nuclei
____ 53. To find the number of neutrons in an isotope, subtract the____.
a.
atomic number from the mass number
b.
mass number from the atomic number
c.
number of isotopes from the mass number
d.
number of protons from the number of electrons
____ 54. The most stable isotope of an atom with 12 protons probably has ____ neutrons.
a.
24
c.
6
b.
18
d.
12
____ 55. The strong nuclear force holds the ____ together.
a.
protons
c.
nucleus
b.
neutrons
d.
electrons
____ 56. Radioactive decay is the release of ____.
a.
radios
c.
nuclear particles and energy
b.
isotopes
d.
light
____ 57. A(n) ____ particle consists of two protons and two neutrons.
a.
gamma
c.
beta
b.
alpha
d.
omega
____ 58. The changing of one element into another in radioactive decay is called ____.
a.
transmutation
c.
half-life
b.
radiation
d.
a chain reaction
____ 59. Radioactive decay can be affected by ____.
a.
the weather
c.
increased pressure
b.
magnetic fields
d.
none of these
____ 60. A radioactive isotope has a half-life of 100 years. A sample of 40 g of the isotope will have a mass of ____ g in 200 years.
a.
120
c.
20
b.
40
d.
10
____ 61. Tracer elements can be used without danger to people because they have ____ half-lives.
a.
short
c.
strong
b.
long
d.
nonexistent
Completion
Complete each statement.
62. Most of the mass of an atom is located in its ____________________.
63. Atoms that are unstable are more likely to be ____________________ than atoms that are stable.
64. The high-energy electrons given off during radioactive decay are called ____________________.
65. Of the three main subatomic particles, the ____________________ has the least mass.
66. The type of glass tube that Crookes and Thomson used for their experiments is called a(n) ____________________ tube.
67. The stream of particles in a cathode-ray tube travels from the cathode to the ____________________.
68. The likely location of the negatively charged particles in an atom is called a(n) ____________________.
69. Atoms of the same element containing different numbers of neutrons are called ____________________.
Complete the following sentences using the terms listed below. Some terms may not be used.
atoms
anode
predictable
cathode
sphere
cloud
random
tracer elements
archaeology
chemistry
70. The study of matter is called ____________________.
71. Different elements are made up of different kinds of ____________________.
72. A(n) ____________________ is an electrode that has a positive charge.
73. A(n) ____________________ is an electrode that has a negative charge.
74. An electron cloud is shaped like a(n) ____________________ with the nucleus at its center.
75. Radioactive decay is a(n) ____________________ process.
76. Isotopes called ____________________ are used to diagnose disease and to study environmental conditions.
Choose the best of the three choices in parentheses.
77. The Greeks named what they believed to be the tiniest particle of matter a(n) ____________________ (proton, atom, cell).
78. An element is made up of only one kind of ____________________ (isotope, atom, particle).
79. Research using ____________________ (television, atomic bombs, cathode rays) led scientists to believe that the atom could be broken down into smaller particles.
80. A(n) ____________________ (electron, proton, neutron) is electrically neutral.
81. An atomic nucleus is often most stable if the number of protons is ____________________ (equal to, greater than, less than) the number of neutrons.
82. Atoms of the same element always have the same number of ____________________ (neutrons, electrons, protons).
83. To find the number of neutrons in an isotope, start with the mass number and ______________________________ (add the atomic number, subtract the atomic number, multiply by two).
84. If you have 16 g of a substance that has a half-life of 3 days, after 12 days you will have ____________________ (8, 1, 0) g of the substance remaining.
Matching
Match each isotope with the correct statement below.
a.
carbon-14
c.
iodine-131
b.
americium-241
d.
phosphorus-32
____ 85. used to study plant growth and reproduction
____ 86. used to determine the age of once-living artifacts
____ 87. used in the diagnosis of thyroid disease
____ 88. used in many smoke detectors
Match each scientist with the correct statement below.
a.
Thomson
c.
Crookes
b.
Dalton
d.
Rutherford
____ 89. Almost all the mass of an atom is located in its nucleus.
____ 90. Different elements are made of different types of atoms.
____ 91. Cathode rays are made up of negatively charged particles.
____ 92. used the cathode-ray tube to discover streams of particles
Match each item with the correct description below.
a.
neutron
h.
half-life
b.
mass number
i.
isotopes
c.
atomic number
j.
transmutation
d.
element
k.
alpha particle
e.
beta particle
l.
proton
f.
electron cloud
m.
radioactive decay
g.
electron
n.
average atomic mass
____ 93. matter that is made up of only one kind of atom
____ 94. a negatively charged particle that is part of every kind of matter
____ 95. a positively charged particle that is present in the nucleus of all atoms
____ 96. uncharged particle in the nucleus of an atom
____ 97. region surrounding the nucleus in which the electrons move about
____ 98. the number of protons in the nucleus of an atom of an element
____ 99. atoms of the same element that have different numbers of neutrons
____ 100. the number of neutrons plus protons in the nucleus of an atom
____ 101. the mass of the mixture of the isotopes for an element
____ 102. the release of nuclear particles and energy
____ 103. the changing of one element into another element through radioactive decay
____ 104. particle consisting of two protons and two neutrons
____ 105. a high-energy electron that comes from the nucleus, not from the electron cloud
____ 106. the amount of time required for half a sample of a radioactive isotope to decay
Short Answer
107.
Why do you think the electron cloud theory is the current and accepted model of the atom and how it works?
108.
It took many years and the work of many scientists to discover how atoms work.
Part A Explain why scientific collaboration and use of other scientific theories is important for the advancement of science and the development of human culture.
Part B Explain what further research about atoms and atomic theories can do for the advancement of science and human culture.
109.
Use Thomson’s cathode-ray experiments to explain why the neutron was the last of the three main subatomic particles to be discovered.
110.
Explain why an isotope with a half-life of 7 years would not be a good choice for a tracer element used to diagnose illnesses.
111.
Name three key differences between beta particles and ordinary electrons.
112.
Dalton thought that all the atoms of an element were identical. Based on what you have learned, how would you modify Dalton’s definition of an element?
113.
The model of the atom proposed by Greek philosophers appears similar to the model proposed centuries later by Dalton. What was the key difference between the two models?
114.
One isotope of helium is called helium-4. Knowing that helium has an atomic number of 2, explain why an alpha particle is sometimes referred to as a helium nucleus.
115.
How would the results of Rutherford’s metal foil experiment have been different if he had bombarded the foil with beta particles instead of alpha particles?
116.
Could carbon-14 be used to date a stone arrowhead found at an ancient burial site? Explain your reasoning.
117.
Where do the stream of particles in a cathode-ray tube come from? What provides the energy for their release?
118.
Explain why the mass of electrons can be ignored when the mass number of an atom is calculated.
119.
Suppose a scientist wants to isolate the isotopes of hydrogen (hydrogen-1, hydrogen-2, and hydrogen-3) from a sample of hydrogen. What property of the isotopes would the scientist need to rely on when designing a separation method?
120.
Suppose you had a 2-g sample of carbon-14 and a 2-g sample of iodine-131. If you used a Geiger counter to measure radioactive decay, which sample would show the larger initial rate of decay? Give a reason for your answer. How would the rates of decay change over a period of a week?
121.
Americium-241, which is used in home smoke detectors, has a half-life of about 400 years, yet manufacturers recommend discarding home smoke detectors after ten years. Could a homeowner install a smoke detector containing americium-241 and use it for decades if he or she replaces the battery once a year?
122.
The elements with atomic numbers 43 and 61 (technetium and promethium) are the only two of the elements from atomic number 1 to atomic number 83 that cannot be found in nature. What can you infer about the isotopes of technetium and promethium? Could these elements have existed in nature when Earth was first formed?
123.
The scientists who developed the modern theory of atomic structure never saw an atom. In general, on what did they base their theories?
124.
Carbon-14 dating cannot be used for nonliving materials or for materials that are older than about 50,000 years. Propose a related method scientists could use to date older, nonliving materials.
125.
Make a sketch of the solar system showing the Sun and the planets. Use the sketch to draw an analogy between the solar system and the structure of an atom. How are the two systems similar? How are they different?
Number of Subatomic Particles in Selected Isotopes
Isotope
Number of protons
Number of neutrons
Number of electrons
magnesium-24
12
magnesium-26
12
chlorine-35
18
chlorine-37
17
Table 14-1
126.
Use what you know about atomic structure to fill in the missing data in Table 14-1.
127.
Propose a model of matter that explains how atoms, which contain so much empty space, can combine to form materials such as a copper pipe or an aluminum pan that appear so solid.
128.
Suppose you were constructing a time line of developments that contributed to the modern model of the atom. Place the following events in the order that they would appear on the time line. Begin with the earliest event.
______ a. Thomson’s evidence for the existence of positive particles in atoms
______ b. Rutherford’s metal foil experiment
______ c. discovery of the neutron
______ d. the description of an atom as the smallest particle of matter
______ e. Crookes' experiments with the cathode-ray tube
129. Study the following diagram. Then label each part using the correct terms from the list.
electron
electron cloud
neutron
nucleus
proton
Use your knowledge of atomic structure to answer the following questions.
Atom
Number of protons
Number of neutrons
Number of electrons
Atomic number
Mass number
a
6
6
12
b
0
1
1
c
11
11
23
d
8
6
6
e
17
17
35
f
12
12
12
g
10
9
9
130. What are the missing values from the table?
131. Which two are isotopes of one another? Explain why they are isotopes.
132. Which two atoms could be the “before” and “after” of an alpha ejection?
133. Which atom could not possibly emit an alpha particle? Why?
134. In an outline, the subtopics are neutron, proton, and electron. What is the main topic?
135. In an outline, the subtopics are fossil dating, cancer detection, and circulation problems. What is the main topic?
136. An atom has a mass number of 53 and an atomic number of 26. How many neutrons does it have? Include a formula that explains your calculation.
137. The isotopes of carbon (carbon-12, carbon-13, and carbon-14) have different mass numbers. Each isotope has six protons. Explain how you can determine the number of neutrons in each isotope.
138. A certain element has a half-life of 20 years. A scientist starts with 100 g of the element.
a. How many grams remain after 20 years?
b. How many grams remain after 40 years?
c. How many half-lives are there in a 100-year span? How many grams of the sample would remain at the end of the 100 years?
Problem
Figure 14-1
139.
Figure 14-1 shows the decay of a sample of neptunium-238 over a period of 10 days. What is the half-life of neptunium-238?
140.
If the original sample in Figure 14-1 contains 0.620 g, how much neptunium-238 will remain after 4 days? How much will remain after 8 days?
141.
Uranium is the element with atomic number 92. Uranium-235 is a radioactive isotope that decays by emitting alpha particles. What is the atomic number of the new element that forms? What is its mass number?
142.
Thorium is the element with atomic number 90. Thorium-231 is a radioactive isotope that decays by emitting beta particles. What is the atomic number of the new element that forms? What is its mass number?
Essay
143. How is americium-241 used in smoke detectors?
7th Grade - Chapter 3 ONLINE REVEIW
Answer Section
TRUE/FALSE
1. ANS: T PTS: 1
2. ANS: F PTS: 1
3. ANS: T PTS: 1
4. ANS: T PTS: 1
5. ANS: F PTS: 1
6. ANS: F PTS: 1
7. ANS: F PTS: 1
8. ANS: T PTS: 1
MODIFIED TRUE/FALSE
9. ANS: F, ancient Greeks
PTS: 1 DIF: Webb's I OBJ: 2/1 STA: SC.H.1.3.6 SC.H.3.3.5
10. ANS: T PTS: 1 DIF: Webb's I
OBJ: 3/1 STA: SC.A.1.3.1 SC.A.2.3.2
11. ANS: T PTS: 1 DIF: Webb's I
OBJ: 5/2 STA: SC.A.2.3.2
12. ANS: F, neutron
PTS: 1 DIF: Webb's I OBJ: 3/1 STA: SC.A.2.3.2
13. ANS: F, atomic number
PTS: 1 DIF: Webb's I OBJ: 3/1 STA: SC.A.2.3.2
14. ANS: T PTS: 1 DIF: Webb's I
OBJ: 5/2
15. ANS: F, protons
PTS: 1 DIF: Webb's I OBJ: 3/1 STA: SC.A.2.3.2
16. ANS: F, less
PTS: 1 DIF: Webb's I OBJ: 3/1 STA: SC.A.2.3.2
MULTIPLE CHOICE
17. ANS: B PTS: 1 DIF: Webb's II STA: SC.H.1.3.1
18. ANS: D PTS: 1 DIF: Webb's I STA: SC.A.1.3.1
19. ANS: C PTS: 1 DIF: Webb's I STA: SC.H.1.3.1
20. ANS: C PTS: 1 DIF: Webb's I STA: SC.H.1.3.1 SC.A.2.3.2
21. ANS: B PTS: 1 DIF: Webb's II
STA: SC.H.1.3.1 SC.H.1.3.6 SC.H.3.3.5
22. ANS: D PTS: 1 DIF: Webb's I STA: SC.A.2.3.2
23. ANS: A PTS: 1 DIF: Webb's I STA: SC.A.2.3.2
24. ANS: D PTS: 1 DIF: Webb's II STA: SC.A.2.3.2
25. ANS: B PTS: 1 DIF: Webb's II STA: SC.A.2.3.2
26. ANS: C PTS: 1 DIF: Webb's II STA: SC.A.2.3.2 SC.D.1.3.5
27. ANS: C PTS: 1 DIF: Webb's II STA: SC.A.2.3.2 SC.D.1.3.5
28. ANS: C PTS: 1 DIF: Webb's I
29. ANS: A PTS: 1 DIF: Webb's II STA: SC.A.1.3.1
30. ANS: C PTS: 1 DIF: Webb's I OBJ: 3/1
STA: SC.A.2.3.2
31. ANS: B PTS: 1 DIF: Webb's I OBJ: 3/1
32. ANS: A PTS: 1 DIF: Webb's I OBJ: 5/2
STA: SC.A.2.3.2
33. ANS: D PTS: 1 DIF: Webb's I OBJ: 5/2
34. ANS: B PTS: 1 DIF: Webb's I OBJ: 3/1
STA: SC.A.2.3.2
35. ANS: C PTS: 1 DIF: Webb's I OBJ: 2/1
STA: SC.H.1.3.1 SC.H.1.3.6
36. ANS: B PTS: 1 DIF: Webb's I OBJ: 2/1
STA: SC.H.1.3.1 SC.H.1.3.6
37. ANS: C PTS: 1 DIF: Webb's I OBJ: 2/1
STA: SC.H.1.3.1 SC.H.1.3.6
38. ANS: D PTS: 1 DIF: Webb's II OBJ: 1/1
STA: SC.A.2.3.1 SC.A.2.3.2
39. ANS: A PTS: 1 DIF: Webb's I OBJ: 5/2
STA: SC.A.2.3.2
40. ANS: D PTS: 1 DIF: Webb's I OBJ: 5/2
STA: SC.A.2.3.2
41. ANS: A PTS: 1 DIF: Webb's I OBJ: 1/1
STA: SC.H.1.3.1 SC.H.1.3.6
42. ANS: D PTS: 1 DIF: Webb's I OBJ: 3/1
STA: SC.A.2.3.2
43. ANS: B PTS: 1 DIF: Webb's I OBJ: 5/2
44. ANS: B PTS: 1 DIF: Webb's I OBJ: 6/2
45. ANS: B PTS: 1
46. ANS: C PTS: 1
47. ANS: A PTS: 1
48. ANS: A PTS: 1
49. ANS: D PTS: 1
50. ANS: D PTS: 1
51. ANS: B PTS: 1
52. ANS: C PTS: 1
53. ANS: A PTS: 1
54. ANS: D PTS: 1
55. ANS: C PTS: 1
56. ANS: C PTS: 1
57. ANS: B PTS: 1
58. ANS: A PTS: 1
59. ANS: D PTS: 1
60. ANS: D PTS: 1
61. ANS: A PTS: 1
COMPLETION
62. ANS: nucleus
PTS: 1 DIF: Webb's I OBJ: 3/1 STA: SC.A.2.3.2
63. ANS: radioactive
PTS: 1 DIF: Webb's I OBJ: 4/1 STA: SC.A.2.3.2
64. ANS: beta particles
PTS: 1 DIF: Webb's I OBJ: 4/1 STA: SC.A.2.3.2
65. ANS: electron
PTS: 1 DIF: Webb's I OBJ: 3/1 STA: SC.A.2.3.2
66. ANS: cathode-ray
PTS: 1 DIF: Webb's I OBJ: 1/1 STA: SC.H.1.3.6
67. ANS: anode
PTS: 1 DIF: Webb's I OBJ: 1/1
68. ANS: electron cloud
PTS: 1 DIF: Webb's I OBJ: 3/1 STA: SC.A.2.3.2
69. ANS: isotopes
PTS: 1 DIF: Webb's I OBJ: 5/2 STA: SC.A.2.3.2
70. ANS: chemistry
PTS: 1
71. ANS: atoms
PTS: 1
72. ANS: anode
PTS: 1
73. ANS: cathode
PTS: 1
74. ANS: sphere
PTS: 1
75. ANS: random
PTS: 1
76. ANS: tracer elements
PTS: 1
77. ANS: atom
PTS: 1
78. ANS: atom
PTS: 1
79. ANS: cathode rays
PTS: 1
80. ANS: neutron
PTS: 1
81. ANS: equal to
PTS: 1
82. ANS: protons
PTS: 1
83. ANS: subtract the atomic number
PTS: 1
84. ANS: 1
PTS: 1
MATCHING
85. ANS: D PTS: 1 DIF: Webb's I OBJ: 6/2
86. ANS: A PTS: 1 DIF: Webb's I OBJ: 6/2
87. ANS: C PTS: 1 DIF: Webb's I OBJ: 6/2
88. ANS: B PTS: 1 DIF: Webb's I OBJ: 6/2
89. ANS: D PTS: 1 DIF: Webb's I OBJ: 2/1
STA: SC.A.2.3.2
90. ANS: B PTS: 1 DIF: Webb's I OBJ: 2/1
STA: SC.A.2.3.2
91. ANS: A PTS: 1 DIF: Webb's I OBJ: 1/1
STA: SC.A.2.3.1 SC.A.2.3.2
92. ANS: C PTS: 1 DIF: Webb's I OBJ: 1/1
STA: SC.A.2.3.1 SC.A.2.3.2
93. ANS: D PTS: 1
94. ANS: G PTS: 1
95. ANS: L PTS: 1
96. ANS: A PTS: 1
97. ANS: F PTS: 1
98. ANS: C PTS: 1
99. ANS: I PTS: 1
100. ANS: B PTS: 1
101. ANS: N PTS: 1
102. ANS: M PTS: 1
103. ANS: J PTS: 1
104. ANS: K PTS: 1
105. ANS: E PTS: 1
106. ANS: H PTS: 1
SHORT ANSWER
107. ANS:
The theory accounts for recent research that explains the unpredictable nature of electrons. The behavior of electrons is more comparable to that of waves than of particles. Electrons are also more likely to be found close to the nucleus because they are attracted to the positive charges of the protons. The electrons in the region surrounding the nucleus create a cloud-like appearance, which explains the name “electron cloud model.”
PTS: 1 DIF: Webb's II STA: SC.A.2.3.2 SC.H.1.3.1
108. ANS:
Part A Answers will vary, but may include the idea that scientific theories often build on each other over time. For example, one scientist may make discoveries about protons, enabling another group of scientists to do further research. Further research may uncover information about neutrons or other related information. This helps advance science and human culture by providing people with more general knowledge about life.
Part B Further exploration about atoms and atomic theories enables general scientific knowledge to increase. It also allows for possible cures for diseases and can save many lives.
PTS: 1 DIF: Webb's III STA: SC.H.1.3.6 SC.H.3.3.5
109. ANS:
Thomson used magnetic fields to detect charged particles in his cathode-ray tube. Because neutrons have no charge, the cathode-ray tube did not detect them.
PTS: 1 DIF: Webb's II OBJ: 1/1 STA: SC.H.1.3.1 SC.H.1.3.6
110. ANS:
A small quantity of the isotope would not decay quickly enough to produce the desired effect, if the isotope were absorbed into body tissues, the patient would be exposed to a prolonged and most likely damaging, dose of radiation.
PTS: 1 DIF: Webb's II OBJ: 6/2 STA: SC.A.2.3.3
111. ANS:
Beta particles 1) are emitted from the atom during radioactive decay, 2) originate in the nucleus when a neutron splits into a proton and electron, and 3) have higher energies than ordinary electrons.
PTS: 1 DIF: Webb's II OBJ: 5/2 STA: SC.A.2.3.2
112. ANS:
All atoms of an element are not identical. Many elements have more than one isotope. Although each atom of an element has the same number of protons, the numbers of neutrons in the atom's nucleus can vary.
PTS: 1 DIF: Webb's II OBJ: 2/1
STA: SC.A.2.3.2 SC.H.1.3.1 SC.H.1.3.6
113. ANS:
Dalton’s model was based on scientific research and open to challenge by further studies. The Greeks used logic, but they did not do experiments. Dalton also added the idea of different atoms for different elements.
PTS: 1 DIF: Webb's II OBJ: 2/1 STA: SC.H.1.3.1 SC.H.1.3.6
114. ANS:
An alpha particle consists of two protons and two neutrons, the same four particles as in a helium-4 nucleus (mass number 4 – atomic number 2).
PTS: 1 DIF: Webb's II OBJ: 5/2 STA: SC.A.2.3.2
115. ANS:
The paths of beta particles that passed near the nucleus would have been deflected in a different direction because of the force of attraction between the electrons and protons.
PTS: 1 DIF: Webb's II OBJ: 1/1 STA: SC.A.2.3.2
116. ANS:
No, carbon-14 can be used to date objects that were once alive, not objects like stone that were never alive. An organism had to absorb carbon-14 as a natural part of metabolism so that the decay process could begin when it died.
PTS: 1 DIF: Webb's II OBJ: 5/2
117. ANS:
The stream of particles are emitted by the cathode. The high-voltage electrical source supplies the energy for their release.
PTS: 1 DIF: Webb's II OBJ: 1/1 STA: SC.A.2.3.1
118. ANS:
Protons and neutrons in the nucleus account for almost all the mass of an atom. The electrons are almost without mass and perhaps can be explained as waves rather than particles.
PTS: 1 DIF: Webb's II OBJ: 3/1 STA: SC.A.2.3.2
119. ANS:
The scientist would need to rely on the difference in mass.
PTS: 1 DIF: Webb's II OBJ: 5/2
120. ANS:
The iodine-131 would show the larger initial decay because it has a much shorter half-life. The decay of iodine-131 would drop off dramatically during the week; there would be no noticeable change in decay for the carbon-14 sample.
PTS: 1 DIF: Webb's II OBJ: 6/2
121. ANS:
Theoretically, an isotope with a half-life of 400 years should provide enough alpha particles to allow the smoke detector to work for many more years. However, the sample of americium-241 in the detector may be so small that the number of alpha particles emitted drops below the needed level. Also, the reliability of other parts in the detector may be limited to ten years. The smoke detector should be replaced.
PTS: 1 DIF: Webb's II OBJ: 6/2
122. ANS:
Technetium and promethium have no stable isotopes. These two elements could have existed long ago, but any deposits of these elements have long since decayed.
PTS: 1 DIF: Webb's II OBJ: 5/2
123. ANS:
They based their theories on the observed behavior of atoms and of subatomic particles. For example, they couldn’t see an electron, but they could observe behavior of electrons in a cathode-ray tube. As they learned more about the behavior, they modified their theories.
PTS: 1 DIF: Webb's II OBJ: 2/1 STA: SC.H.1.3.1 SC.H.1.3.3
124. ANS:
Find a radioactive isotope of an element that is commonly found in rocks. The isotope would need to have a long half-life.
PTS: 1 DIF: Webb's II OBJ: 6/2
125. ANS:
Students may compare the Sun and the planets to the nucleus and electrons. The gravitational attraction between the Sun and planets can be compared to the attraction between electrons and protons in the nucleus. There is a lot of empty space in both systems. Unlike electrons, the planets are not identical. In contrast to the electron cloud, the location of the planets in relation to the Sun is definite. Electrons are likely to be close to the nucleus, but they could be anywhere.
PTS: 1 DIF: Webb's III OBJ: 3/1 STA: SC.A.2.3.2 SC.E.1.3.1
126. ANS:
Number of Subatomic Particles in Selected Isotopes
Isotope
Number of protons
Number of neutrons
Number of electrons
magnesium-24
12
12
12
magnesium-26
12
14
12
chlorine-35
17
18
17
chlorine-37
17
20
17
PTS: 1 DIF: Webb's II OBJ: 5/2 STA: SC.A.2.3.2
127. ANS:
Students’ models will probably focus on the large number of atoms and their possible arrangements. One possible analogy could use a chain link fence. With a single layer of fencing, the holes in the fence are obvious and easy to penetrate. With multiple layers placed one on top of the other, the structure becomes more solid and a path through the layers much less direct.
PTS: 1 DIF: Webb's III OBJ: 3/1 STA: SC.A.2.3.2
128. ANS:
D, E, A, B, C
PTS: 1 DIF: Webb's II OBJ: 2/1 STA: SC.H.1.3.6
129. ANS:
PTS: 1
130. ANS:
a. 6, 6
b. 1, 1
c. 12, 11
d. 6, 14
e. 18, 17
f. 12, 24
g. 9, 19
PTS: 1
131. ANS:
Atom a and atom d are isotopes. They have the same atomic number, or number of protons, but different mass numbers because the number of neutrons is different.
PTS: 1
132. ANS:
Atom c could be the “before” of an alpha ejection, and atom g could be the “after.”
PTS: 1
133. ANS:
Atom b, which has one proton and no neutrons, could not possibly emit an alpha particle, which consists of two protons and two neutrons.
PTS: 1
134. ANS:
Answers will vary slightly. Topics should indicate that neutrons, protons, and electrons are particles within atoms.
PTS: 1
135. ANS:
Answers will vary slightly. Topics should indicate uses of radioactive isotopes.
PTS: 1
136. ANS:
number of neutrons = mass number – atomic number
53 – 26 = 27
PTS: 1
137. ANS:
The number of neutrons in an atom, including isotopes of the same element, can be calculated by subtracting the atomic number from the mass number.
For carbon-12: number of neutrons = 12 – 6 = 6
For carbon-13: number of neutrons = 13 – 6 = 7
For carbon-14: number of neutrons = 14 – 6 = 8
PTS: 1
138. ANS:
PTS: 1
PROBLEM
139. ANS:
2 days
PTS: 1 DIF: Webb's II OBJ: 5/2
140. ANS:
0.155 g; 0.0388 g
PTS: 1 DIF: Webb's II OBJ: 5/2
141. ANS:
atomic number = 90; mass number = 231
PTS: 1 DIF: Webb's II OBJ: 5/2 STA: SC.A.2.3.2
142. ANS:
atomic number = 91; mass number = 231
PTS: 1 DIF: Webb's II OBJ: 4/1 STA: SC.A.2.3.2
ESSAY
143. ANS:
Americium-241 undergoes transmutation to neptunium by ejecting an alpha particle. The air in a smoke detector can conduct electricity because of the presence of the alpha particles. As long as the electric current flows, the smoke detector stays silent. If smoke enters the detector, the current is interrupted and the alarm sounds.
PTS: 1
Wednesday, January 9, 2008
7th Grade- Chapter 2 Online Review
7th Grade - Chapter 2 ONLINE REVIEW
Modified True/False
Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement true.
____ 1. The ability to burn is an example of a physical property. _________________________
____ 2. The state of matter is an example of a physical property. _________________________
____ 3. Ice, liquid water, and water vapor are the three states of water. _________________________
____ 4. The odor of a substance is an example of a physical property. _________________________
____ 5. Burning wood is an example of physical change. _________________________
____ 6. Physical changes are difficult or impossible to reverse. _________________________
____ 7. Sugar dissolved in tea and sugar in a bowl are not the same substance. _________________________
____ 8. The cracks that form in a sidewalk during winter are the result of a physical change. _________________________
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____ 9. When Genevieve smells a flower, she is showing an example of which kind of property of matter?
a.
chemical
b.
deposition
c.
physical
d.
vaporization
____ 10. Which state of matter do milk, juice, and vegetable oil represent?
a.
chemical
b.
gas
c.
liquid
d.
solid
____ 11. Which physical property of matter does NOT depend on the size of an object?
a.
density
b.
mass
c.
volume
d.
weight
____ 12. On a sunny winter day, Richard sees that the snow on the ground is beginning to melt. Which can he conclude about the temperature that day?
a.
The temperature was cold enough to turn a liquid into a solid.
b.
The weight of the snow was a factor in the increase in temperature.
c.
The temperature was warm enough to reach the melting point for snow.
d.
The density of the snow was a factor in the increase in temperature.
____ 13. If the mass of an object is 10 and its volume is 5, what is its density?
a.
1
b.
1.2
c.
2
d.
3
____ 14. When Marianne burns a log in the fireplace, which kind of property of matter is she demonstrating?
a.
chemical
b.
gas
c.
physical
d.
solubility
____ 15. Paul is looking around in his environment and observing the kinds of change that occur every day. He makes this chart of examples of change.
Which kinds of change do his examples represent?
a.
change in composition
b.
change in mass
c.
chemical change
d.
physical change
____ 16. What is the process called when a liquid changes into a gas?
a.
condensation
b.
deposition
c.
sublimation
d.
vaporization
____ 17. An old nail sometimes develops a reddish appearance called rust. Which term describes this change?
a.
chemical
b.
dissolving
c.
physical
d.
tarnish
____ 18. Rachel is finding that chemical changes occur in many different ways.
What could you conclude about the chemical changes listed in her chart?
a.
Chemical changes do not form new substances.
b.
During a chemical change, a substance absorbs energy.
c.
Energy is released during a chemical change.
d.
The formation of gas is due to a chemical change.
____ 19. Which type of change does a strong odor in rotting food indicate?
a.
change in solubility
b.
change in sublimation
c.
chemical change
d.
physical change
____ 20. What scientific law explains that the total mass of matter is the same before and after a physical change?
a.
Law of Conservation of Gases
b.
Law of Conservation of Mass
c.
Law of Conservation of Matter
d.
Law of Conservation of Weight
____ 21. People in Karen’s community recycle materials such as plastics, glass, and aluminum. Which is the BEST explanation for the reason for recycling?
a.
Household waste products are useless and cannot be reused.
b.
Recycling costs more than throwing materials into garbage dumps.
c.
Recycling forces people to separate their garbage and think about what they use.
d.
Waste products can be turned into new products using chemical and physical changes.
____ 22. The measurement of an object's mass is a ____.
a.
physical change
c.
chemical change
b.
physical property
d.
chemical property
____ 23. The ability of an apple to change color when exposed to air is a ____.
a.
physical property
c.
physical change
b.
chemical property
d.
chemical change
____ 24. The ability of a pond to freeze over in winter is a ____.
a.
physical property
c.
physical change
b.
chemical property
d.
chemical change
____ 25. Which of the following is NOT a possible sign of a chemical change?
a.
a change in state
c.
the release of a gas
b.
a change in color
d.
the release of energy
____ 26. Which of the following is NOT a possible sign of a physical change?
a.
a change in appearance
c.
the release of energy
b.
a change in volume
d.
a change in color
____ 27. When a newspaper is left in direct sunlight for a few days, the paper begins to turn yellow. The yellow color is evidence of a ____.
a.
physical property
c.
physical change
b.
chemical property
d.
chemical change
____ 28. Three examples of physical change are ____.
a.
boiling water, a nail rusting, a melting candle
b.
a pond freezing, breaking glass, a burning candle
c.
melting ice, mowing the lawn, carving a statue
d.
applying lipstick, making lemonade, baking bread
____ 29. When a chunk of dry ice is at room temperature, a cloud of carbon dioxide vapor forms. The carbon dioxide is changing from a ____.
a.
solid to a liquid
c.
liquid to plasma
b.
solid to a gas
d.
liquid to a gas
____ 30. Which of these is not a physical property of matter?
a.
density
c.
ability to burn
b.
mass
d.
texture
____ 31. An example of physical change involving more than one substance is ____.
a.
evaporating
c.
burning
b.
rusting
d.
dissolving
____ 32. An example of a change of state is ____.
a.
evaporating
c.
burning
b.
rusting
d.
dissolving
____ 33. Which of the following shows a behavioral property?
a.
peeling a banana
c.
snow melting in the Sun
b.
iron attracted to a lodestone
d.
hammer hitting a nail
____ 34. The ____ is an example of a chemical change.
a.
melting of chocolate
c.
salting of food
b.
freezing of water
d.
burning of paper
____ 35. Which of the following is an example of a chemical change?
a.
evaporating
c.
burning
b.
melting
d.
sublimation
____ 36. Which of these indicates that a chemical change has taken place?
a.
change from a liquid to a gas
c.
release of heat energy
b.
change in shape
d.
dissolving of a solid
____ 37. The density of a material is ____.
a.
how much the material weighs
b.
the mass of a unit volume of the material
c.
how much space the material takes up
d.
whether or not the material floats in a liquid
____ 38. The process of a liquid changing into a gas is called ____.
a.
sublimation
c.
vaporization
b.
condensation
d.
deposition
____ 39. The process of a gas changing into a liquid is called ____.
a.
sublimation
c.
vaporization
b.
condensation
d.
deposition
____ 40. The process of a solid changing directly into a gas, without ever becoming a liquid is called ____.
a.
sublimation
c.
vaporization
b.
condensation
d.
deposition
____ 41. The process in which a gas changes directly into a solid, without ever becoming a liquid is called ____.
a.
sublimation
c.
vaporization
b.
condensation
d.
deposition
____ 42. An object’s odor is a ____.
a.
physical property
c.
physical change
b.
chemical property
d.
chemical change
____ 43. A change in an object’s odor is the result of a ____.
a.
physical property
c.
physical change
b.
chemical property
d.
chemical change
____ 44. The precipitation of a solid can indicate a ____.
a.
physical property
c.
physical change
b.
chemical property
d.
chemical change
Completion
Complete each statement.
45. Photosynthesis in plants is an example of a ____________________ change.
46. The color of a material is an example of a ____________________ property.
47. The main difference between physical and chemical changes is that ____________________ changes are not reversible.
48. The evaporation of water is an example of a change in ____________________.
Unscramble the letters to form the correct word for each definition.
49. hacclime preptory: allows a substance to change to a new substance ____________________
50. malceich hagcen: original material is transformed into a new material ____________________
51. aeioocnnrstv fo sams: total mass is the same before and after a physical or chemical change ____________________
52. chyplais gnache: any alteration in size, shape, or form of matter ____________________
53. tendisy: relates an object’s mass to the amount of space it takes up ____________________
54. saphicly toppyrer: most of these characteristics can be observed with the senses ____________________
55. liigbon tnpoi: temperature at which a liquid turns into a gas ____________________
56. vhaiebro: how something acts ____________________
57. ulmove: how much space an object takes up ____________________
58. mtlgnei iotpn: temperature at which a solid turns into a liquid ____________________
59. ttsae: solid, liquid or gas ____________________
60. aaaceenrpp: properties you detect with your senses ____________________
61. Shape, color, and texture are examples of ____________________.
62. You can tell a(n) ____________________ has occurred when energy is taken in or given off.
63. The rusting of metal is an example of a(n) ____________________ change.
64. A change of ____________________ is an example of a physical change.
65. Milk and gasoline are examples of the ____________________ of matter.
66. Mass and volume depend on the ____________________ of matter.
67. ____________________ measures how much mass is in a given volume.
68. You can use a table to find the ____________________ point of most substances.
69. The fact that something is magnetic can be determined by watching its ____________________.
70. A(n) ____________________ can only be determined by changing a substance.
71. ____________________ is when a gas changes into a solid.
72. ____________________ can indicate physical or chemical changes depending on the cause of the change.
73. Energy is ____________________ in a chemical change.
74. Formation of a(n) ____________________ is an indication of chemical change.
75. The total ____________________ of the matter is the same before and after a physical or chemical change. This is the ______________________________.
Classify the following changes by writing physical or chemical.
76. tearing paper ____________________
77. wax melting ____________________
78. wood burning ____________________
79. peeling a potato ____________________
80. iron rusting ____________________
81. sanding wood ____________________
82. milk souring ____________________
83. silver tarnishing ____________________
Matching
Match the type of property with the example.
a.
physical property
b.
chemical property
____ 84. a box measures 4 cm by 3 cm by 8 cm
____ 85. the liquid burned easily
____ 86. the muffins baked for 20 minutes until done
____ 87. the dessert tasted rich and chocolatey
Match the signs of chemical change with the examples of chemical change.
a.
the formation of a precipitate
c.
release of light and heat
b.
a change in color
d.
the formation of a gas
____ 88. burning wood in a fireplace
____ 89. antacid tablet in water
____ 90. solution of sodium nitrate is mixed with a solution of lead nitrate
____ 91. leaving peeled fruit on a kitchen counter
Match each item to the correct statement below.
a.
state
g.
physical change
b.
boiling point
h.
physical property
c.
chemical change
i.
behavior
d.
chemical property
j.
release of energy
e.
density
k.
mass
f.
color
l.
liquid
____ 92. an indication that a chemical change has taken place
____ 93. temperature at which liquid changes to gas
____ 94. a physical property of matter
____ 95. size, shape, or state of matter
____ 96. measure of how much of an object there is
____ 97. property that could be used to indicate physical or chemical change
____ 98. Melting is an example.
____ 99. The ability to burn is an example.
____ 100. liquid, gas, or solid
____ 101. how something acts
____ 102. a state of matter
____ 103. Rusting of iron is an example.
Short Answer
104.
Explain the difference between a physical and a chemical property.
105.
Why is the state of matter a physical property and not a chemical property?
106.
Why should you never taste anything in the laboratory unless your teacher tells you it's okay?
107.
How can you tell that fireworks exploded during a typical Fourth of July display don't all contain exactly the same ingredients?
108.
Describe five physical properties of a lemon, three that are constant for every lemon and two that can vary from lemon to lemon.
109.
Explain why the appearance of a gas is not always a sign of a chemical change.
110.
Sometimes people collect items such as eggshells, lawn clippings, and leaves into a compost heap in the backyard. The pile should be turned over once or twice a year to release heat that builds up in the center. What do you think is happening inside the compost pile?
111.
Explain how color can be classified as both a physical property and as one indication of a chemical change.
112.
Suppose someone goes to a salon to get his or her hair trimmed, bleached, and braided. Identify which of these processes involves a chemical change and a physical change. Explain your answers.
113.
What is the difference between a chemical change and a physical change?
114.
In the fall, you rake leaves into a pile, burn them, and spread the ashes back on the lawn as fertilizer. What are the chemical changes and what are the physical changes in this process?
115.
When yeast is added to bread dough, it produces carbon dioxide. The pressure of the gas causes the dough to expand. Explain how the rising of dough is an example of both a physical and a chemical change.
116.
Suppose a customer brings a gold bracelet to a jeweler and asks for it to be changed into a gold ring. What property will distinguish the ring from the bracelet? Will the changes required be physical or chemical? Explain your answer.
117.
Auto bodies have usually been made almost entirely from steel, and the main ingredient of steel is iron. However, on many cars, doors and fenders are made of plastic. What key advantage might plastic have over an iron-based material?
118.
Describe three items that you might prepare for breakfast that are changed chemically or physically during preparation.
119.
When a shiny penny turns dull, is the change physical or chemical?
120.
Explain why it is safe to eat table salt even though it is made from sodium, which can burn in water, and chlorine, which is a poisonous gas.
121.
Rock salt is used on winter roads to control icing. Cars become covered with salt from the road. However, salt on a car is not rock salt but powdered salt. Use your knowledge of physical and chemical changes to explain the change in the salt.
122.
Explain how water causes weathering in rocks.
123.
Identify the following properties of matter as size dependent or size independent: density, state, weight, color, volume, ability to attract a magnet, solubility, mass, melting/boiling point.
124.
Define the law of conservation of mass and explain how it relates to physical and chemical changes.
125. List some physical properties that are size dependent.
126. List some physical properties that are size independent.
Think of a piece of notebook paper as you answer the following questions.
127. List three ways you could change the physical properties of the piece of paper.
128. In what ways can you change its chemical properties?
129. Do you think most people cause physical or chemical changes to notebook paper? How?
130. Compare and contrast the changes a piece of paper undergoes when it is torn into tiny pieces and when it is burned.
131. Compare and contrast chemical and physical changes.
132. How does the formation of drops of water on the outside of a glass of iced tea indicate the presence of water vapor, an invisible gas, in the air surrounding the glass? What kind of change is involved in this process?
133. When does the color change in a leaf indicate physical change and when does it indicate chemical change?
134. In a mixture of iron filings and sulfur powder, the particles of each substance are clearly visible and a magnet can be used to separate the iron from the sulfur. After the mixture is heated strongly, neither substance is recognizable and the resulting product is not magnetic. Explain what happened.
135. What is the difference between dissolving sugar in water and making cookies with sugar in them?
136. Classify each of the following properties of sucrose as chemical or physical.
a. It has a melting point of 186°C.
b. It is white solid.
c. It decomposes above 200°C.
d. Its density is 1.58 g/cm3.
e. Its consumption produces 52 kJ of energy per teaspoon.
Essay
137.
Physical changes are sometimes easier to identify than chemical changes.
Part A Give an example of a chemical change that occurs seasonally in a tree.
Part B Explain the process of the chemical change.
138. Why is an object’s mass a size-dependent physical property while its density is a size-independent physical property?
139. Using what you know about chemical change and the law of conservation of mass, explain why you think many communities no longer allow residents to burn fallen leaves each autumn.
7th Grade - Chapter 2 ONLINE REVIEW
Answer Section
MODIFIED TRUE/FALSE
1. ANS: F, chemical
PTS: 1 DIF: Webb's I OBJ: 1/1 STA: SC.A.1.3.5
2. ANS: T PTS: 1 DIF: Webb's I
OBJ: 1/1 STA: SC.A.1.3.5
3. ANS: T PTS: 1 DIF: Webb's I
OBJ: 1/1 STA: SC.A.1.3.5
4. ANS: T PTS: 1 DIF: Webb's I
OBJ: 1/1 STA: SC.A.1.3.5
5. ANS: F, chemical
PTS: 1 DIF: Webb's I OBJ: 4/2 STA: SC.A.1.3.5
6. ANS: F, Chemical
PTS: 1 DIF: Webb's I OBJ: 4/2 STA: SC.A.1.3.5
7. ANS: F, are
PTS: 1 DIF: Webb's I OBJ: 3/2 STA: SC.A.1.3.5
8. ANS: T PTS: 1 DIF: Webb's I
OBJ: 3/2 STA: SC.A.1.3.5
MULTIPLE CHOICE
9. ANS: A PTS: 1 DIF: Webb's I STA: SC.A.1.3.1
10. ANS: C PTS: 1 DIF: Webb's I STA: SC.A.1.3.1
11. ANS: A PTS: 1 DIF: Webb's I STA: SC.A.1.3.1
12. ANS: C PTS: 1 DIF: Webb's II STA: SC.A.1.3.1 SC.A.1.3.5
13. ANS: C PTS: 1 DIF: Webb's II STA: SC.A.1.3.1
14. ANS: A PTS: 1 DIF: Webb's I STA: SC.A.1.3.1 SC.A.1.3.5
15. ANS: D PTS: 1 DIF: Webb's II STA: SC.A.1.3.5
16. ANS: D PTS: 1 DIF: Webb's I STA: SC.A.1.3.5
17. ANS: A PTS: 1 DIF: Webb's I STA: SC.A.1.3.5
18. ANS: C PTS: 1 DIF: Webb's II STA: SC.A.1.3.5
19. ANS: C PTS: 1 DIF: Webb's I STA: SC.A.1.3.5
20. ANS: B PTS: 1 DIF: Webb's I STA: SC.A.1.3.5
21. ANS: D PTS: 1 DIF: Webb's II STA: SC.A.1.3.5 SC.G.2.3.4
22. ANS: B PTS: 1 DIF: Webb's I OBJ: 1/1
STA: SC.A.1.3.2 SC.A.1.3.5
23. ANS: B PTS: 1 DIF: Webb's I OBJ: 1/1
STA: SC.A.1.3.5
24. ANS: A PTS: 1 DIF: Webb's I OBJ: 1/1
STA: SC.A.1.3.5
25. ANS: A PTS: 1 DIF: Webb's II OBJ: 4/2
STA: SC.A.1.3.5
26. ANS: C PTS: 1 DIF: Webb's II OBJ: 4/2
STA: SC.A.1.3.5
27. ANS: D PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.A.1.3.5
28. ANS: C PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.A.1.3.5
29. ANS: B PTS: 1 DIF: Webb's II OBJ: 3/2
STA: SC.A.1.3.5
30. ANS: C PTS: 1
31. ANS: D PTS: 1
32. ANS: A PTS: 1
33. ANS: B PTS: 1
34. ANS: D PTS: 1
35. ANS: C PTS: 1
36. ANS: C PTS: 1
37. ANS: B PTS: 1
38. ANS: C PTS: 1
39. ANS: B PTS: 1
40. ANS: A PTS: 1
41. ANS: D PTS: 1
42. ANS: A PTS: 1
43. ANS: D PTS: 1
44. ANS: D PTS: 1
COMPLETION
45. ANS: chemical
PTS: 1 DIF: Webb's I OBJ: 3/2 STA: SC.A.1.3.5
46. ANS: physical
PTS: 1 DIF: Webb's I OBJ: 1/1 STA: SC.A.1.3.5
47. ANS: chemical
PTS: 1 DIF: Webb's I OBJ: 4/2 STA: SC.A.1.3.5
48. ANS: state
PTS: 1 DIF: Webb's I OBJ: 3/2 STA: SC.A.1.3.5
49. ANS: chemical property
PTS: 1
50. ANS: chemical change
PTS: 1
51. ANS: conservation of mass
PTS: 1
52. ANS: physical change
PTS: 1
53. ANS: density
PTS: 1
54. ANS: physical property
PTS: 1
55. ANS: boiling point
PTS: 1
56. ANS: behavior
PTS: 1
57. ANS: volume
PTS: 1
58. ANS: melting point
PTS: 1
59. ANS: state
PTS: 1
60. ANS: appearance
PTS: 1
61. ANS: physical properties
PTS: 1
62. ANS: chemical change
PTS: 1
63. ANS: chemical
PTS: 1
64. ANS: state
PTS: 1
65. ANS: liquid state
PTS: 1
66. ANS: amount
PTS: 1
67. ANS: Density
PTS: 1
68. ANS:
melting
boiling
PTS: 1
69. ANS: behavior
PTS: 1
70. ANS: chemical property
PTS: 1
71. ANS: Deposition
PTS: 1
72. ANS: Color
PTS: 1
73. ANS:
gained
released
PTS: 1
74. ANS:
gas
solid
PTS: 1
75. ANS: mass, law of conservation of mass
PTS: 1
76. ANS: physical
PTS: 1
77. ANS: physical
PTS: 1
78. ANS: chemical
PTS: 1
79. ANS: physical
PTS: 1
80. ANS: chemical
PTS: 1
81. ANS: physical
PTS: 1
82. ANS: chemical
PTS: 1
83. ANS: chemical
PTS: 1
MATCHING
84. ANS: A PTS: 1 DIF: Webb's II OBJ: 1/1
STA: SC.A.1.3.5
85. ANS: B PTS: 1 DIF: Webb's II OBJ: 1/1
STA: SC.A.1.3.5
86. ANS: B PTS: 1 DIF: Webb's II OBJ: 1/1
STA: SC.A.1.3.5
87. ANS: A PTS: 1 DIF: Webb's II OBJ: 1/1
STA: SC.A.1.3.5
88. ANS: C PTS: 1 DIF: Webb's II OBJ: 3/2
STA: SC.A.1.3.5
89. ANS: D PTS: 1 DIF: Webb's II OBJ: 3/2
STA: SC.A.1.3.5
90. ANS: A PTS: 1 DIF: Webb's II OBJ: 3/2
STA: SC.A.1.3.5
91. ANS: B PTS: 1 DIF: Webb's II OBJ: 3/2
STA: SC.A.1.3.5
92. ANS: J PTS: 1
93. ANS: B PTS: 1
94. ANS: E PTS: 1
95. ANS: H PTS: 1
96. ANS: K PTS: 1
97. ANS: F PTS: 1
98. ANS: G PTS: 1
99. ANS: D PTS: 1
100. ANS: A PTS: 1
101. ANS: I PTS: 1
102. ANS: L PTS: 1
103. ANS: C PTS: 1
SHORT ANSWER
104. ANS:
A chemical property is a characteristic that cannot be observed without altering the substance observed. A physical property is a characteristic that a person can observe without changing the composition of that substance.
PTS: 1 DIF: Webb's II STA: SC.A.1.3.1
105. ANS:
Changing state does not change the identity of the matter. Water is still water whether it is ice, liquid, or vapor. Chemical properties can't be observed without changing the substance.
PTS: 1 DIF: Webb's II OBJ: 1/1 STA: SC.A.1.3.5
106. ANS:
There could be a poisonous residue on the glassware, or a chemical change may have occurred, causing something to become poisonous.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.A.1.3.1 SC.A.1.3.5
107. ANS:
The starting materials must differ because the materials produced during the explosions have different colors.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.A.1.3.5
108. ANS:
Constant: color, taste, texture of skin; not constant: size, shape
PTS: 1 DIF: Webb's II OBJ: 1/1 STA: SC.A.1.3.5
109. ANS:
A gas can be the result of a change of state, which is a physical change. The boiling of water produces water vapor; opening a carbonated beverage releases dissolved carbon dioxide.
PTS: 1 DIF: Webb's II OBJ: 4/2 STA: SC.A.1.3.4
110. ANS:
The material is decomposing, which is a chemical change; heat is the evidence of change.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.A.1.3.5
111. ANS:
Color is a physical property because it can be observed without changing the substance, but when new substances form during a chemical change, there may be a change in color because the new substances will have a different set of physical properties.
PTS: 1 DIF: Webb's II OBJ: 4/2 STA: SC.A.1.3.5
112. ANS:
The trimming and braiding are physical changes because they are changes in size and shape. The bleaching is a chemical change because it produces a change in color.
PTS: 1 DIF: Webb's II OBJ: 4/2 STA: SC.A.1.3.5
113. ANS:
A chemical change changes the substance. A physical change doesn't affect the basics of the substance.
PTS: 1 DIF: Webb's II OBJ: 2/1 STA: SC.A.1.3.5
114. ANS:
Raking the leaves into a pile and spreading the ashes are physical changes. Burning the leaves and the ashes being broken down by the lawn for fertilizer are chemical changes.
PTS: 1 DIF: Webb's II OBJ: 4/2 STA: SC.A.1.3.5
115. ANS:
The carbon dioxide gas produced indicates that a chemical change has occurred. The change in volume as the dough rises is an example of a physical change.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.A.1.3.5
116. ANS:
shape; physical; The solid bracelet must be heated until it melts, then liquid gold must be poured into a ring-shaped mold and allowed to harden. The new ring will still have the same composition as the bracelet.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.A.1.3.5
117. ANS:
Plastic doesn't rust when exposed to the oxygen in air and water. (Also, the plastic rebounds from gentle impacts, and a car with less density is more fuel efficient.)
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.A.1.3.5
118. ANS:
Possible choices: physically changing a banana by peeling and slicing; physically changing water by heating; physically changing oranges to make juice; chemically changing bread by toasting; chemically changing eggs or meat by cooking.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.A.1.3.5
119. ANS:
chemical; the metal in the penny has combined with oxygen in the air
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.A.1.3.5
120. ANS:
The product of a chemical change can have very different physical and chemical properties from the original materials.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.A.1.3.1 SC.A.1.3.5
121. ANS:
The rock salt dissolved in water from snow or rain. The water evaporated from the surface of the car leaving powdered salt, a physical change.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.A.1.3.5
122. ANS:
Water can freeze and expand in the crevices of rocks, causing them to split into smaller pieces. Water can also dissolve materials from rocks.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.A.1.3.1 SC.A.1.3.5
123. ANS:
size dependent: mass, weight, volume; size independent: density, melting/boiling point, solubility, ability to attract a magnet, state, color
PTS: 1 DIF: Webb's II OBJ: 1/1 STA: SC.A.1.3.1 SC.A.1.3.5
124. ANS:
The law of conservation of mass states that mass cannot be created or destroyed. This means that the mass of any substances present before a physical or chemical change is equal to the mass of the substances present after the change.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.A.1.3.2 SC.A.1.3.5
125. ANS:
Answers may include mass, weight, volume.
PTS: 1
126. ANS:
Answers may include density, melting point, boiling point, solubility, ability to attract a magnet, state of matter, color.
PTS: 1
127. ANS:
Possible answers include: coloring the paper, crumpling the paper, tearing it, or dissolving it.
PTS: 1
128. ANS:
Burn it or dissolve it in acid.
PTS: 1
129. ANS:
Most people cause physical changes because they use notebook paper to take notes or write things on. Very few people burn notebook paper.
PTS: 1
130. ANS:
The tearing of paper is a physical change. The only changes in the paper caused by tearing are changes in size and shape. The burning of paper is a chemical change. During this change, paper is changed into ashes, smoke, and gases.
PTS: 1
131. ANS:
Both change the substance from what is first seen. Chemical changes are not easily reversed. Physical changes just change the observable parts of a substance, but the basic substance is unchanged.
PTS: 1
132. ANS:
The formation of the water drops indicates that water vapor in the air has condensed, or changed to a liquid, on the sides of the glass. Condensation is a physical change.
PTS: 1
133. ANS:
If the color change is caused by a reaction within the leaf, it is chemical. If it is caused by bird droppings or berry juice, it is physical.
PTS: 1
134. ANS:
Heating caused a chemical change to take place. The chemical properties of the new product have changed and a new substance has been formed.
PTS: 1
135. ANS:
Dissolving sugar in water is a physical change. Making cookies with sugar is a chemical change.
PTS: 1
136. ANS:
a. physical
b. physical
c. chemical
d. physical
e. chemical
PTS: 1
ESSAY
137. ANS:
Part A In the fall, the leaves of many trees begin to change color. This is a visible example of a chemical change that is occurring in the tree.
Part B In the fall, the chlorophyll in the tree’s leaves undergoes a chemical change into colorless chemicals. This allows different colors of pigment such as red and orange now to be seen.
PTS: 1 DIF: Webb's II STA: SC.A.1.3.5
138. ANS:
Mass, weight, and volume of an object are size dependent; they are greater or less, depending on the size of the object. Size-independent physical properties are the same, regardless of the paper’s size. Density, which is mass divided by volume, does not change with size.
PTS: 1
139. ANS:
Answers will vary. Look for answers that define chemical change and the law of conservation of mass and relate the mass of fallen leaves to an equal amount of particles that could pollute the air.
PTS: 1
Modified True/False
Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement true.
____ 1. The ability to burn is an example of a physical property. _________________________
____ 2. The state of matter is an example of a physical property. _________________________
____ 3. Ice, liquid water, and water vapor are the three states of water. _________________________
____ 4. The odor of a substance is an example of a physical property. _________________________
____ 5. Burning wood is an example of physical change. _________________________
____ 6. Physical changes are difficult or impossible to reverse. _________________________
____ 7. Sugar dissolved in tea and sugar in a bowl are not the same substance. _________________________
____ 8. The cracks that form in a sidewalk during winter are the result of a physical change. _________________________
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____ 9. When Genevieve smells a flower, she is showing an example of which kind of property of matter?
a.
chemical
b.
deposition
c.
physical
d.
vaporization
____ 10. Which state of matter do milk, juice, and vegetable oil represent?
a.
chemical
b.
gas
c.
liquid
d.
solid
____ 11. Which physical property of matter does NOT depend on the size of an object?
a.
density
b.
mass
c.
volume
d.
weight
____ 12. On a sunny winter day, Richard sees that the snow on the ground is beginning to melt. Which can he conclude about the temperature that day?
a.
The temperature was cold enough to turn a liquid into a solid.
b.
The weight of the snow was a factor in the increase in temperature.
c.
The temperature was warm enough to reach the melting point for snow.
d.
The density of the snow was a factor in the increase in temperature.
____ 13. If the mass of an object is 10 and its volume is 5, what is its density?
a.
1
b.
1.2
c.
2
d.
3
____ 14. When Marianne burns a log in the fireplace, which kind of property of matter is she demonstrating?
a.
chemical
b.
gas
c.
physical
d.
solubility
____ 15. Paul is looking around in his environment and observing the kinds of change that occur every day. He makes this chart of examples of change.
Which kinds of change do his examples represent?
a.
change in composition
b.
change in mass
c.
chemical change
d.
physical change
____ 16. What is the process called when a liquid changes into a gas?
a.
condensation
b.
deposition
c.
sublimation
d.
vaporization
____ 17. An old nail sometimes develops a reddish appearance called rust. Which term describes this change?
a.
chemical
b.
dissolving
c.
physical
d.
tarnish
____ 18. Rachel is finding that chemical changes occur in many different ways.
What could you conclude about the chemical changes listed in her chart?
a.
Chemical changes do not form new substances.
b.
During a chemical change, a substance absorbs energy.
c.
Energy is released during a chemical change.
d.
The formation of gas is due to a chemical change.
____ 19. Which type of change does a strong odor in rotting food indicate?
a.
change in solubility
b.
change in sublimation
c.
chemical change
d.
physical change
____ 20. What scientific law explains that the total mass of matter is the same before and after a physical change?
a.
Law of Conservation of Gases
b.
Law of Conservation of Mass
c.
Law of Conservation of Matter
d.
Law of Conservation of Weight
____ 21. People in Karen’s community recycle materials such as plastics, glass, and aluminum. Which is the BEST explanation for the reason for recycling?
a.
Household waste products are useless and cannot be reused.
b.
Recycling costs more than throwing materials into garbage dumps.
c.
Recycling forces people to separate their garbage and think about what they use.
d.
Waste products can be turned into new products using chemical and physical changes.
____ 22. The measurement of an object's mass is a ____.
a.
physical change
c.
chemical change
b.
physical property
d.
chemical property
____ 23. The ability of an apple to change color when exposed to air is a ____.
a.
physical property
c.
physical change
b.
chemical property
d.
chemical change
____ 24. The ability of a pond to freeze over in winter is a ____.
a.
physical property
c.
physical change
b.
chemical property
d.
chemical change
____ 25. Which of the following is NOT a possible sign of a chemical change?
a.
a change in state
c.
the release of a gas
b.
a change in color
d.
the release of energy
____ 26. Which of the following is NOT a possible sign of a physical change?
a.
a change in appearance
c.
the release of energy
b.
a change in volume
d.
a change in color
____ 27. When a newspaper is left in direct sunlight for a few days, the paper begins to turn yellow. The yellow color is evidence of a ____.
a.
physical property
c.
physical change
b.
chemical property
d.
chemical change
____ 28. Three examples of physical change are ____.
a.
boiling water, a nail rusting, a melting candle
b.
a pond freezing, breaking glass, a burning candle
c.
melting ice, mowing the lawn, carving a statue
d.
applying lipstick, making lemonade, baking bread
____ 29. When a chunk of dry ice is at room temperature, a cloud of carbon dioxide vapor forms. The carbon dioxide is changing from a ____.
a.
solid to a liquid
c.
liquid to plasma
b.
solid to a gas
d.
liquid to a gas
____ 30. Which of these is not a physical property of matter?
a.
density
c.
ability to burn
b.
mass
d.
texture
____ 31. An example of physical change involving more than one substance is ____.
a.
evaporating
c.
burning
b.
rusting
d.
dissolving
____ 32. An example of a change of state is ____.
a.
evaporating
c.
burning
b.
rusting
d.
dissolving
____ 33. Which of the following shows a behavioral property?
a.
peeling a banana
c.
snow melting in the Sun
b.
iron attracted to a lodestone
d.
hammer hitting a nail
____ 34. The ____ is an example of a chemical change.
a.
melting of chocolate
c.
salting of food
b.
freezing of water
d.
burning of paper
____ 35. Which of the following is an example of a chemical change?
a.
evaporating
c.
burning
b.
melting
d.
sublimation
____ 36. Which of these indicates that a chemical change has taken place?
a.
change from a liquid to a gas
c.
release of heat energy
b.
change in shape
d.
dissolving of a solid
____ 37. The density of a material is ____.
a.
how much the material weighs
b.
the mass of a unit volume of the material
c.
how much space the material takes up
d.
whether or not the material floats in a liquid
____ 38. The process of a liquid changing into a gas is called ____.
a.
sublimation
c.
vaporization
b.
condensation
d.
deposition
____ 39. The process of a gas changing into a liquid is called ____.
a.
sublimation
c.
vaporization
b.
condensation
d.
deposition
____ 40. The process of a solid changing directly into a gas, without ever becoming a liquid is called ____.
a.
sublimation
c.
vaporization
b.
condensation
d.
deposition
____ 41. The process in which a gas changes directly into a solid, without ever becoming a liquid is called ____.
a.
sublimation
c.
vaporization
b.
condensation
d.
deposition
____ 42. An object’s odor is a ____.
a.
physical property
c.
physical change
b.
chemical property
d.
chemical change
____ 43. A change in an object’s odor is the result of a ____.
a.
physical property
c.
physical change
b.
chemical property
d.
chemical change
____ 44. The precipitation of a solid can indicate a ____.
a.
physical property
c.
physical change
b.
chemical property
d.
chemical change
Completion
Complete each statement.
45. Photosynthesis in plants is an example of a ____________________ change.
46. The color of a material is an example of a ____________________ property.
47. The main difference between physical and chemical changes is that ____________________ changes are not reversible.
48. The evaporation of water is an example of a change in ____________________.
Unscramble the letters to form the correct word for each definition.
49. hacclime preptory: allows a substance to change to a new substance ____________________
50. malceich hagcen: original material is transformed into a new material ____________________
51. aeioocnnrstv fo sams: total mass is the same before and after a physical or chemical change ____________________
52. chyplais gnache: any alteration in size, shape, or form of matter ____________________
53. tendisy: relates an object’s mass to the amount of space it takes up ____________________
54. saphicly toppyrer: most of these characteristics can be observed with the senses ____________________
55. liigbon tnpoi: temperature at which a liquid turns into a gas ____________________
56. vhaiebro: how something acts ____________________
57. ulmove: how much space an object takes up ____________________
58. mtlgnei iotpn: temperature at which a solid turns into a liquid ____________________
59. ttsae: solid, liquid or gas ____________________
60. aaaceenrpp: properties you detect with your senses ____________________
61. Shape, color, and texture are examples of ____________________.
62. You can tell a(n) ____________________ has occurred when energy is taken in or given off.
63. The rusting of metal is an example of a(n) ____________________ change.
64. A change of ____________________ is an example of a physical change.
65. Milk and gasoline are examples of the ____________________ of matter.
66. Mass and volume depend on the ____________________ of matter.
67. ____________________ measures how much mass is in a given volume.
68. You can use a table to find the ____________________ point of most substances.
69. The fact that something is magnetic can be determined by watching its ____________________.
70. A(n) ____________________ can only be determined by changing a substance.
71. ____________________ is when a gas changes into a solid.
72. ____________________ can indicate physical or chemical changes depending on the cause of the change.
73. Energy is ____________________ in a chemical change.
74. Formation of a(n) ____________________ is an indication of chemical change.
75. The total ____________________ of the matter is the same before and after a physical or chemical change. This is the ______________________________.
Classify the following changes by writing physical or chemical.
76. tearing paper ____________________
77. wax melting ____________________
78. wood burning ____________________
79. peeling a potato ____________________
80. iron rusting ____________________
81. sanding wood ____________________
82. milk souring ____________________
83. silver tarnishing ____________________
Matching
Match the type of property with the example.
a.
physical property
b.
chemical property
____ 84. a box measures 4 cm by 3 cm by 8 cm
____ 85. the liquid burned easily
____ 86. the muffins baked for 20 minutes until done
____ 87. the dessert tasted rich and chocolatey
Match the signs of chemical change with the examples of chemical change.
a.
the formation of a precipitate
c.
release of light and heat
b.
a change in color
d.
the formation of a gas
____ 88. burning wood in a fireplace
____ 89. antacid tablet in water
____ 90. solution of sodium nitrate is mixed with a solution of lead nitrate
____ 91. leaving peeled fruit on a kitchen counter
Match each item to the correct statement below.
a.
state
g.
physical change
b.
boiling point
h.
physical property
c.
chemical change
i.
behavior
d.
chemical property
j.
release of energy
e.
density
k.
mass
f.
color
l.
liquid
____ 92. an indication that a chemical change has taken place
____ 93. temperature at which liquid changes to gas
____ 94. a physical property of matter
____ 95. size, shape, or state of matter
____ 96. measure of how much of an object there is
____ 97. property that could be used to indicate physical or chemical change
____ 98. Melting is an example.
____ 99. The ability to burn is an example.
____ 100. liquid, gas, or solid
____ 101. how something acts
____ 102. a state of matter
____ 103. Rusting of iron is an example.
Short Answer
104.
Explain the difference between a physical and a chemical property.
105.
Why is the state of matter a physical property and not a chemical property?
106.
Why should you never taste anything in the laboratory unless your teacher tells you it's okay?
107.
How can you tell that fireworks exploded during a typical Fourth of July display don't all contain exactly the same ingredients?
108.
Describe five physical properties of a lemon, three that are constant for every lemon and two that can vary from lemon to lemon.
109.
Explain why the appearance of a gas is not always a sign of a chemical change.
110.
Sometimes people collect items such as eggshells, lawn clippings, and leaves into a compost heap in the backyard. The pile should be turned over once or twice a year to release heat that builds up in the center. What do you think is happening inside the compost pile?
111.
Explain how color can be classified as both a physical property and as one indication of a chemical change.
112.
Suppose someone goes to a salon to get his or her hair trimmed, bleached, and braided. Identify which of these processes involves a chemical change and a physical change. Explain your answers.
113.
What is the difference between a chemical change and a physical change?
114.
In the fall, you rake leaves into a pile, burn them, and spread the ashes back on the lawn as fertilizer. What are the chemical changes and what are the physical changes in this process?
115.
When yeast is added to bread dough, it produces carbon dioxide. The pressure of the gas causes the dough to expand. Explain how the rising of dough is an example of both a physical and a chemical change.
116.
Suppose a customer brings a gold bracelet to a jeweler and asks for it to be changed into a gold ring. What property will distinguish the ring from the bracelet? Will the changes required be physical or chemical? Explain your answer.
117.
Auto bodies have usually been made almost entirely from steel, and the main ingredient of steel is iron. However, on many cars, doors and fenders are made of plastic. What key advantage might plastic have over an iron-based material?
118.
Describe three items that you might prepare for breakfast that are changed chemically or physically during preparation.
119.
When a shiny penny turns dull, is the change physical or chemical?
120.
Explain why it is safe to eat table salt even though it is made from sodium, which can burn in water, and chlorine, which is a poisonous gas.
121.
Rock salt is used on winter roads to control icing. Cars become covered with salt from the road. However, salt on a car is not rock salt but powdered salt. Use your knowledge of physical and chemical changes to explain the change in the salt.
122.
Explain how water causes weathering in rocks.
123.
Identify the following properties of matter as size dependent or size independent: density, state, weight, color, volume, ability to attract a magnet, solubility, mass, melting/boiling point.
124.
Define the law of conservation of mass and explain how it relates to physical and chemical changes.
125. List some physical properties that are size dependent.
126. List some physical properties that are size independent.
Think of a piece of notebook paper as you answer the following questions.
127. List three ways you could change the physical properties of the piece of paper.
128. In what ways can you change its chemical properties?
129. Do you think most people cause physical or chemical changes to notebook paper? How?
130. Compare and contrast the changes a piece of paper undergoes when it is torn into tiny pieces and when it is burned.
131. Compare and contrast chemical and physical changes.
132. How does the formation of drops of water on the outside of a glass of iced tea indicate the presence of water vapor, an invisible gas, in the air surrounding the glass? What kind of change is involved in this process?
133. When does the color change in a leaf indicate physical change and when does it indicate chemical change?
134. In a mixture of iron filings and sulfur powder, the particles of each substance are clearly visible and a magnet can be used to separate the iron from the sulfur. After the mixture is heated strongly, neither substance is recognizable and the resulting product is not magnetic. Explain what happened.
135. What is the difference between dissolving sugar in water and making cookies with sugar in them?
136. Classify each of the following properties of sucrose as chemical or physical.
a. It has a melting point of 186°C.
b. It is white solid.
c. It decomposes above 200°C.
d. Its density is 1.58 g/cm3.
e. Its consumption produces 52 kJ of energy per teaspoon.
Essay
137.
Physical changes are sometimes easier to identify than chemical changes.
Part A Give an example of a chemical change that occurs seasonally in a tree.
Part B Explain the process of the chemical change.
138. Why is an object’s mass a size-dependent physical property while its density is a size-independent physical property?
139. Using what you know about chemical change and the law of conservation of mass, explain why you think many communities no longer allow residents to burn fallen leaves each autumn.
7th Grade - Chapter 2 ONLINE REVIEW
Answer Section
MODIFIED TRUE/FALSE
1. ANS: F, chemical
PTS: 1 DIF: Webb's I OBJ: 1/1 STA: SC.A.1.3.5
2. ANS: T PTS: 1 DIF: Webb's I
OBJ: 1/1 STA: SC.A.1.3.5
3. ANS: T PTS: 1 DIF: Webb's I
OBJ: 1/1 STA: SC.A.1.3.5
4. ANS: T PTS: 1 DIF: Webb's I
OBJ: 1/1 STA: SC.A.1.3.5
5. ANS: F, chemical
PTS: 1 DIF: Webb's I OBJ: 4/2 STA: SC.A.1.3.5
6. ANS: F, Chemical
PTS: 1 DIF: Webb's I OBJ: 4/2 STA: SC.A.1.3.5
7. ANS: F, are
PTS: 1 DIF: Webb's I OBJ: 3/2 STA: SC.A.1.3.5
8. ANS: T PTS: 1 DIF: Webb's I
OBJ: 3/2 STA: SC.A.1.3.5
MULTIPLE CHOICE
9. ANS: A PTS: 1 DIF: Webb's I STA: SC.A.1.3.1
10. ANS: C PTS: 1 DIF: Webb's I STA: SC.A.1.3.1
11. ANS: A PTS: 1 DIF: Webb's I STA: SC.A.1.3.1
12. ANS: C PTS: 1 DIF: Webb's II STA: SC.A.1.3.1 SC.A.1.3.5
13. ANS: C PTS: 1 DIF: Webb's II STA: SC.A.1.3.1
14. ANS: A PTS: 1 DIF: Webb's I STA: SC.A.1.3.1 SC.A.1.3.5
15. ANS: D PTS: 1 DIF: Webb's II STA: SC.A.1.3.5
16. ANS: D PTS: 1 DIF: Webb's I STA: SC.A.1.3.5
17. ANS: A PTS: 1 DIF: Webb's I STA: SC.A.1.3.5
18. ANS: C PTS: 1 DIF: Webb's II STA: SC.A.1.3.5
19. ANS: C PTS: 1 DIF: Webb's I STA: SC.A.1.3.5
20. ANS: B PTS: 1 DIF: Webb's I STA: SC.A.1.3.5
21. ANS: D PTS: 1 DIF: Webb's II STA: SC.A.1.3.5 SC.G.2.3.4
22. ANS: B PTS: 1 DIF: Webb's I OBJ: 1/1
STA: SC.A.1.3.2 SC.A.1.3.5
23. ANS: B PTS: 1 DIF: Webb's I OBJ: 1/1
STA: SC.A.1.3.5
24. ANS: A PTS: 1 DIF: Webb's I OBJ: 1/1
STA: SC.A.1.3.5
25. ANS: A PTS: 1 DIF: Webb's II OBJ: 4/2
STA: SC.A.1.3.5
26. ANS: C PTS: 1 DIF: Webb's II OBJ: 4/2
STA: SC.A.1.3.5
27. ANS: D PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.A.1.3.5
28. ANS: C PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.A.1.3.5
29. ANS: B PTS: 1 DIF: Webb's II OBJ: 3/2
STA: SC.A.1.3.5
30. ANS: C PTS: 1
31. ANS: D PTS: 1
32. ANS: A PTS: 1
33. ANS: B PTS: 1
34. ANS: D PTS: 1
35. ANS: C PTS: 1
36. ANS: C PTS: 1
37. ANS: B PTS: 1
38. ANS: C PTS: 1
39. ANS: B PTS: 1
40. ANS: A PTS: 1
41. ANS: D PTS: 1
42. ANS: A PTS: 1
43. ANS: D PTS: 1
44. ANS: D PTS: 1
COMPLETION
45. ANS: chemical
PTS: 1 DIF: Webb's I OBJ: 3/2 STA: SC.A.1.3.5
46. ANS: physical
PTS: 1 DIF: Webb's I OBJ: 1/1 STA: SC.A.1.3.5
47. ANS: chemical
PTS: 1 DIF: Webb's I OBJ: 4/2 STA: SC.A.1.3.5
48. ANS: state
PTS: 1 DIF: Webb's I OBJ: 3/2 STA: SC.A.1.3.5
49. ANS: chemical property
PTS: 1
50. ANS: chemical change
PTS: 1
51. ANS: conservation of mass
PTS: 1
52. ANS: physical change
PTS: 1
53. ANS: density
PTS: 1
54. ANS: physical property
PTS: 1
55. ANS: boiling point
PTS: 1
56. ANS: behavior
PTS: 1
57. ANS: volume
PTS: 1
58. ANS: melting point
PTS: 1
59. ANS: state
PTS: 1
60. ANS: appearance
PTS: 1
61. ANS: physical properties
PTS: 1
62. ANS: chemical change
PTS: 1
63. ANS: chemical
PTS: 1
64. ANS: state
PTS: 1
65. ANS: liquid state
PTS: 1
66. ANS: amount
PTS: 1
67. ANS: Density
PTS: 1
68. ANS:
melting
boiling
PTS: 1
69. ANS: behavior
PTS: 1
70. ANS: chemical property
PTS: 1
71. ANS: Deposition
PTS: 1
72. ANS: Color
PTS: 1
73. ANS:
gained
released
PTS: 1
74. ANS:
gas
solid
PTS: 1
75. ANS: mass, law of conservation of mass
PTS: 1
76. ANS: physical
PTS: 1
77. ANS: physical
PTS: 1
78. ANS: chemical
PTS: 1
79. ANS: physical
PTS: 1
80. ANS: chemical
PTS: 1
81. ANS: physical
PTS: 1
82. ANS: chemical
PTS: 1
83. ANS: chemical
PTS: 1
MATCHING
84. ANS: A PTS: 1 DIF: Webb's II OBJ: 1/1
STA: SC.A.1.3.5
85. ANS: B PTS: 1 DIF: Webb's II OBJ: 1/1
STA: SC.A.1.3.5
86. ANS: B PTS: 1 DIF: Webb's II OBJ: 1/1
STA: SC.A.1.3.5
87. ANS: A PTS: 1 DIF: Webb's II OBJ: 1/1
STA: SC.A.1.3.5
88. ANS: C PTS: 1 DIF: Webb's II OBJ: 3/2
STA: SC.A.1.3.5
89. ANS: D PTS: 1 DIF: Webb's II OBJ: 3/2
STA: SC.A.1.3.5
90. ANS: A PTS: 1 DIF: Webb's II OBJ: 3/2
STA: SC.A.1.3.5
91. ANS: B PTS: 1 DIF: Webb's II OBJ: 3/2
STA: SC.A.1.3.5
92. ANS: J PTS: 1
93. ANS: B PTS: 1
94. ANS: E PTS: 1
95. ANS: H PTS: 1
96. ANS: K PTS: 1
97. ANS: F PTS: 1
98. ANS: G PTS: 1
99. ANS: D PTS: 1
100. ANS: A PTS: 1
101. ANS: I PTS: 1
102. ANS: L PTS: 1
103. ANS: C PTS: 1
SHORT ANSWER
104. ANS:
A chemical property is a characteristic that cannot be observed without altering the substance observed. A physical property is a characteristic that a person can observe without changing the composition of that substance.
PTS: 1 DIF: Webb's II STA: SC.A.1.3.1
105. ANS:
Changing state does not change the identity of the matter. Water is still water whether it is ice, liquid, or vapor. Chemical properties can't be observed without changing the substance.
PTS: 1 DIF: Webb's II OBJ: 1/1 STA: SC.A.1.3.5
106. ANS:
There could be a poisonous residue on the glassware, or a chemical change may have occurred, causing something to become poisonous.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.A.1.3.1 SC.A.1.3.5
107. ANS:
The starting materials must differ because the materials produced during the explosions have different colors.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.A.1.3.5
108. ANS:
Constant: color, taste, texture of skin; not constant: size, shape
PTS: 1 DIF: Webb's II OBJ: 1/1 STA: SC.A.1.3.5
109. ANS:
A gas can be the result of a change of state, which is a physical change. The boiling of water produces water vapor; opening a carbonated beverage releases dissolved carbon dioxide.
PTS: 1 DIF: Webb's II OBJ: 4/2 STA: SC.A.1.3.4
110. ANS:
The material is decomposing, which is a chemical change; heat is the evidence of change.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.A.1.3.5
111. ANS:
Color is a physical property because it can be observed without changing the substance, but when new substances form during a chemical change, there may be a change in color because the new substances will have a different set of physical properties.
PTS: 1 DIF: Webb's II OBJ: 4/2 STA: SC.A.1.3.5
112. ANS:
The trimming and braiding are physical changes because they are changes in size and shape. The bleaching is a chemical change because it produces a change in color.
PTS: 1 DIF: Webb's II OBJ: 4/2 STA: SC.A.1.3.5
113. ANS:
A chemical change changes the substance. A physical change doesn't affect the basics of the substance.
PTS: 1 DIF: Webb's II OBJ: 2/1 STA: SC.A.1.3.5
114. ANS:
Raking the leaves into a pile and spreading the ashes are physical changes. Burning the leaves and the ashes being broken down by the lawn for fertilizer are chemical changes.
PTS: 1 DIF: Webb's II OBJ: 4/2 STA: SC.A.1.3.5
115. ANS:
The carbon dioxide gas produced indicates that a chemical change has occurred. The change in volume as the dough rises is an example of a physical change.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.A.1.3.5
116. ANS:
shape; physical; The solid bracelet must be heated until it melts, then liquid gold must be poured into a ring-shaped mold and allowed to harden. The new ring will still have the same composition as the bracelet.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.A.1.3.5
117. ANS:
Plastic doesn't rust when exposed to the oxygen in air and water. (Also, the plastic rebounds from gentle impacts, and a car with less density is more fuel efficient.)
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.A.1.3.5
118. ANS:
Possible choices: physically changing a banana by peeling and slicing; physically changing water by heating; physically changing oranges to make juice; chemically changing bread by toasting; chemically changing eggs or meat by cooking.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.A.1.3.5
119. ANS:
chemical; the metal in the penny has combined with oxygen in the air
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.A.1.3.5
120. ANS:
The product of a chemical change can have very different physical and chemical properties from the original materials.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.A.1.3.1 SC.A.1.3.5
121. ANS:
The rock salt dissolved in water from snow or rain. The water evaporated from the surface of the car leaving powdered salt, a physical change.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.A.1.3.5
122. ANS:
Water can freeze and expand in the crevices of rocks, causing them to split into smaller pieces. Water can also dissolve materials from rocks.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.A.1.3.1 SC.A.1.3.5
123. ANS:
size dependent: mass, weight, volume; size independent: density, melting/boiling point, solubility, ability to attract a magnet, state, color
PTS: 1 DIF: Webb's II OBJ: 1/1 STA: SC.A.1.3.1 SC.A.1.3.5
124. ANS:
The law of conservation of mass states that mass cannot be created or destroyed. This means that the mass of any substances present before a physical or chemical change is equal to the mass of the substances present after the change.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.A.1.3.2 SC.A.1.3.5
125. ANS:
Answers may include mass, weight, volume.
PTS: 1
126. ANS:
Answers may include density, melting point, boiling point, solubility, ability to attract a magnet, state of matter, color.
PTS: 1
127. ANS:
Possible answers include: coloring the paper, crumpling the paper, tearing it, or dissolving it.
PTS: 1
128. ANS:
Burn it or dissolve it in acid.
PTS: 1
129. ANS:
Most people cause physical changes because they use notebook paper to take notes or write things on. Very few people burn notebook paper.
PTS: 1
130. ANS:
The tearing of paper is a physical change. The only changes in the paper caused by tearing are changes in size and shape. The burning of paper is a chemical change. During this change, paper is changed into ashes, smoke, and gases.
PTS: 1
131. ANS:
Both change the substance from what is first seen. Chemical changes are not easily reversed. Physical changes just change the observable parts of a substance, but the basic substance is unchanged.
PTS: 1
132. ANS:
The formation of the water drops indicates that water vapor in the air has condensed, or changed to a liquid, on the sides of the glass. Condensation is a physical change.
PTS: 1
133. ANS:
If the color change is caused by a reaction within the leaf, it is chemical. If it is caused by bird droppings or berry juice, it is physical.
PTS: 1
134. ANS:
Heating caused a chemical change to take place. The chemical properties of the new product have changed and a new substance has been formed.
PTS: 1
135. ANS:
Dissolving sugar in water is a physical change. Making cookies with sugar is a chemical change.
PTS: 1
136. ANS:
a. physical
b. physical
c. chemical
d. physical
e. chemical
PTS: 1
ESSAY
137. ANS:
Part A In the fall, the leaves of many trees begin to change color. This is a visible example of a chemical change that is occurring in the tree.
Part B In the fall, the chlorophyll in the tree’s leaves undergoes a chemical change into colorless chemicals. This allows different colors of pigment such as red and orange now to be seen.
PTS: 1 DIF: Webb's II STA: SC.A.1.3.5
138. ANS:
Mass, weight, and volume of an object are size dependent; they are greater or less, depending on the size of the object. Size-independent physical properties are the same, regardless of the paper’s size. Density, which is mass divided by volume, does not change with size.
PTS: 1
139. ANS:
Answers will vary. Look for answers that define chemical change and the law of conservation of mass and relate the mass of fallen leaves to an equal amount of particles that could pollute the air.
PTS: 1
7th Grade- Chapter 1 Online Review
7th Grade - Chapter 1 ONLINE REVIEW
True/False
Indicate whether the statement is true or false.
____ 1. Science has been used throughout history to answer questions about the world.
____ 2. Using a computer graphic is the only effective way to display the data from an experiment.
____ 3. If the results of your experiment do not support your hypothesis, it means that your hypothesis was wrong.
____ 4. Scientific discoveries have been made by people of different races, sexes, cultures, and time periods.
____ 5. There is usually only one correct method that can be used to solve a problem.
____ 6. The number of trials conducted is the same in every experiment.
____ 7. If the results of experiments do not support a prediction, scientists change their predictions.
____ 8. Because the quality of the solution to a problem depends on how well the entire project is carried out, planning is a very important step in science.
____ 9. Although a model was useful for locating the source of an 1871 cholera epidemic, models are rarely useful to scientists trying to solve other problems.
____ 10. Good experiments can only be conducted if you have the latest materials and tools.
____ 11. Modern electronic communications allow people throughout the world to learn quickly about new discoveries.
____ 12. A hypothesis is a statement of fact.
____ 13. Scientific discoveries are made only by professional scientists.
____ 14. Scientific discoveries influence only areas related to our health.
____ 15. Any information gathered from the Internet can be assumed to be accurate.
____ 16. The more trials you can run in an experiment, the more reliable the results.
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____ 17. What is the name for the steps scientists go through to solve problems?
a.
drawing conclusions
b.
forming a hypothesis
c.
research design
d.
scientific method
____ 18. Rita wants to study the history of her town. What type of research will she have to do?
a.
descriptive research
b.
experimental research
c.
research design
d.
variable research
____ 19. Why is a microscope considered technology?
a.
It uses electricity and has lenses.
b.
It uses a technique that helps solve a problem.
c.
Some people use it every day.
d.
It enables people to see details inside cells.
____ 20. How might a scientist show bias in an experiment?
a.
by asking others to verify the data
b.
by choosing a random sample by computer
c.
by drawing conclusions without analyzing data
d.
by using multiple trials to confirm data
____ 21. Mike is testing the effects of friction on a toy car going down a ramp. He runs one trial with sandpaper on the ramp and another trial with cloth on the ramp. What else does he need in his experiment?
a.
a control group
b.
a longer ramp
c.
an independent variable
d.
a technology
____ 22. Margo recorded data for her experiment on a line graph.
What conclusions can she draw from her data?
a.
Growth declined steadily each week.
b.
Growth increased steadily each week.
c.
A growth pattern cannot be determined.
d.
Growth will probably stop soon.
____ 23. What happens after a technological design process is tested successfully?
a.
Design flaws are identified.
b.
The new process is tested with the public.
c.
The constraints are listed.
d.
A pilot plant can be built.
____ 24. Which of the following is NOT a step in the scientific method?
a.
analyze your data
b.
communicate your results
c.
find your biases
d.
test your hypothesis
____ 25. Mike is conducting an experiment to see if his dog will eat a new brand of dog food. He will replace the dog’s old food with the new brand. Identify the dependent variable in this experiment.
a.
the amount of food
b.
the place the food is left
c.
the type of food
d.
whether the dog eats
____ 26. Why is it important for scientists to present their findings to the public?
a.
The public has to understand every scientific finding.
b.
Scientific data can benefit society in different ways.
c.
The scientist might be able to get the data published.
d.
The scientist needs credit for his or her findings.
____ 27. What is the best way to predict when the next full moon will occur?
a.
Collect data about the time of the sunset each day.
b.
Design an engineering experiment.
c.
Draw your own conclusion.
d.
Make a model of the solar system.
____ 28. Clara is conducting an experiment to find out the number of times her lab mice received a reward for finishing a task. She is using a tally chart to keep track of each mouse and the number of rewards each receives.
What is the best type of graph for her to use to analyze her data?
a.
bar graph
b.
line graph
c.
pictograph
d.
pie graph
____ 29. How does engineering meet human needs?
a.
It uses newly designed products.
b.
It solves problems.
c.
It uses technology.
d.
It uses science.
____ 30. Scientists use prior experience to ____.
a.
collect data
b.
make predictions about what will happen under certain circumstances
c.
analyze their data
d.
serve as a control in their experiments
____ 31. One example of technology that is commonly used by scientists is ____.
a.
computers
c.
variables
b.
hypotheses
d.
observations
____ 32. Examples of the skills used in science include ____ and ____.
a.
cholera , E. coli outbreaks
c.
facts , inferences
b.
clues , detectives
d.
observations , measurements
____ 33. After scientists analyze the results of their experiments, they ____.
a.
form hypotheses
b.
include a control
c.
communicate those results to other people
d.
choose the variables they want to test
____ 34. Which of the following steps to solve a problem must be completed first?
a.
analyzing data
c.
forming a hypothesis
b.
recognizing and identifying the problem
d.
testing a hypothesis
____ 35. Which of the following steps to solve a problem is completed last?
a.
analyzing data
c.
drawing conclusions
b.
recognizing and identifying the problem
d.
testing a hypothesis
____ 36. Listing what is known about a problem and possible ways to solve the problem are parts of ____.
a.
making a plan
c.
testing a hypothesis
b.
drawing conclusions
d.
eliminating bias
____ 37. ____ can save time and money by testing ideas that would otherwise be difficult to test quickly or easily.
a.
Biases
c.
Models
b.
Conclusions
d.
Variables
____ 38. A prediction or statement that can be tested is ____.
a.
a conclusion
c.
a control
b.
an observation
d.
a hypothesis
____ 39. A factor in an experiment that can change is ____.
a.
an observation
c.
a control
b.
a variable
d.
a hypothesis
____ 40. A sample that is treated exactly like the other experimental groups except that the variable is not applied to it is a(n) ____.
a.
observation
c.
control
b.
variable
d.
hypothesis
____ 41. Scientists conduct multiple trials of their experiments because ____.
a.
their results are more likely to be reliable
b.
it costs less to run more trials than fewer trials
c.
unusual occurrences are likely to be repeated every time
d.
experiments always have the same results
____ 42. One tool that can be used to display your data is a ____.
a.
balance
c.
microscope
b.
spring scale
d.
computer
____ 43. One way to reduce bias in an experiment is to ____.
a.
ask only girls a question about a school topic
b.
take numerical measurements of the results
c.
use descriptive phrases as your data
d.
make sure that the results come out the way you want them
____ 44. A good way to organize and record your results and observations is ____.
a.
in a data table
b.
by using a calculator
c.
with a balance or spring scale
d.
by having a hypothesis before you begin your experiment
____ 45. Which of the following units is part of the International System of Units, or SI?
a.
pounds
c.
meters
b.
ounces
d.
inches
Completion
Complete each statement.
46. use of knowledge to make products or tools ____________________
47. a prediction or statement that can be tested tools ____________________
48. SI is used for this purpose ____________________
49. sample treated like other experimental groups except no variable is used ____________________
50. sample taken without bias ____________________
51. a factor in an experiment that can change ____________________
52. a way or a process to investigate what is happening around us ____________________
53. way to organize and record results and observations ____________________
Correctly complete each sentence by choosing the best choice in parentheses.
54. Scientists use ______________________________ (observations, experiments, observations and experiments) to find answers to questions.
55. In today’s society, there is/are usually ____________________ (only one, a pair of, several) scientist[s] working on a problem at one time.
56. _________________________ (Making a detailed plan, Making a model, Identifying the problem) is the first step a scientist would take to solve a problem.
57. New artifacts, new techniques, and new social-technical systems are types of ____________________ (scientific discovery, technology, engineering advances).
58. The first step in finding a scientific solution to a problem or human need is ____________________ (make a discovery, define a problem, test a model).
Matching
Match each term with its description below.
a.
hypothesis
e.
science
b.
variable
f.
technology
c.
control
g.
globalization
d.
SI
____ 59. use of knowledge to make products or tools that people can use
____ 60. a sample that is treated exactly like the other experimental groups except that the variable is not applied to it
____ 61. worldwide distribution
____ 62. a system of units used by scientists that is based on units of ten
____ 63. a prediction or statement that can be tested
____ 64. a factor in an experiment that can change
____ 65. a process used to solve a problem
Match a or b to each term below.
a.
general skill used in science
b.
specific step scientists follow to solve problems
____ 66. observing
____ 67. analyzing data
____ 68. forming a hypothesis
____ 69. comparing and contrasting
____ 70. classifying
____ 71. drawing conclusions
____ 72. recognizing the problem
____ 73. testing a hypothesis
____ 74. measuring
Match the description with the correct term. Some items may not be used.
a.
model
g.
control
b.
random
h.
scientist
c.
data table
i.
hypothesis
d.
trial
j.
bias
e.
technology
k.
variable
f.
science log
l.
science
____ 75. a way to record results and observations accurately
____ 76. a single run of an experiment
____ 77. the application of science to make products or tools
____ 78. a way or a process to investigate what is happening around us
____ 79. a prediction or statement that can be tested
____ 80. a slanted view
____ 81. a factor that can change in an experiment
____ 82. used to represent things that happen too slowly or quickly t observe directly
____ 83. a type of sample taken without bias
____ 84. sample treated like other experimental groups except no viable is used
Match the following SI units with what they measure.
a.
temperature
d.
length
b.
liquid volume
e.
mass
c.
area
____ 85. meter
____ 86. gram
____ 87. tonne
____ 88. liter
____ 89. degrees Celsius
Short Answer
90.
Why is it important for all scientists to follow the same general steps when doing scientific investigations?
91.
Dana writes a detailed plan for a scientific investigation. First she shows her plan to her lab partner. He advises that she should use only one independent variable instead of two. She then rewrites her plan to incorporate his comments, and she conducts the experiment.
Part A Why do you think Dana’s lab partner advises against two independent variables in her experiment?
Part B If Dana’s lab partner wants to repeat the experiment, how would he do so?
92.
Give at least two reasons why scientists use the International System of Units (SI).
93.
List at least two reasons for designing your data tables before beginning your experiment.
94.
What are two ways that scientists communicate their results to other people?
95.
List three examples of how technology has made entertainment more accessible to people over the last one hundred years.
96.
Describe how scientists around the world use technology to discuss their results.
97.
How is the work of scientists similar to the work of detectives?
98.
Describe how prior knowledge may be used by scientists.
99.
List three ways that computers can be used in research.
100.
List at least four skills that scientists commonly use.
101.
List at least four types of information that scientists might include in a journal.
102.
Sequence the following steps: test your hypothesis, draw conclusions, recognize the problem, analyze the data, form a hypothesis.
103.
How might scientists go about trying to solve a large, complicated problem?
104.
Give an example of how scientists might use a computer model.
105.
List at least two possible sources of information that you could use to form a hypothesis.
106.
List at least three things you should be careful to do when designing an experiment.
107.
What are at least two factors that might influence the decision about how many trials of an experiment to conduct?
108.
State at least one possible source of bias in an experiment and describe how you can reduce it.
109.
If the results of your experiment do not support your hypothesis, have you still learned something important? Explain.
110.
Besides advances in the entertainment industry, give an example of how technology could make a difference in your everyday life.
111.
Are all scientific discoveries made by professional scientists? Explain.
112.
Describe how new scientific knowledge can challenge old ways of thinking or doing things.
113.
Is all scientific information good? Can some information be harmful? Can science make these decisions?
Figure 1-1
114.
An experiment was conducted to test which of two antibiotics was more effective at killing a certain type of bacterium. Cultures A and B were treated with antibiotic 1; cultures C and D were treated with antibiotic 2; culture E was not treated with any antibiotic. Based on the results shown in Figure 1-1, what conclusion would you draw about which antibiotic is more effective? Explain. What is the purpose of culture E?
115. Number these steps for doing an experiment in the correct order.
a. Test your hypothesis.
b. Analyze your data.
c. Recognize the problem.
d. Form a hypothesis.
e. Communicate your results.
f. Draw conclusions.
116. How do new scientific discoveries affect our everyday life? Give examples.
117. What are some ways that data can be recorded in a science journal?
118. How could you use two beakers, distilled water, two hot plates, two thermometers, and salt to test if adding salt affects the boiling point of water?
119. Complete the following events chain for doing experimental research.
1. Recognize the _________________.
¯
2. Form a ______________________.
¯
3. Select dependent and independent
___________________
รง
Run multiple trials of experiment
¯
4. Identify _____________________.
¯
5. ___________________ your results.
¯
6. Draw ______________________.
¯
communicate
120. Compare and contrast science and technology.
121. Choose an object that you use every day. Explain how science and technology were applied to its development.
122. Explain how the Internet or its parts could be described as an artifact, a technique, and as a social-technical system.
123. What are the main steps of solving a scientific problem?
124. Discuss two advantages of using the International System of Units, or SI, for measurements in scientific research.
Essay
125. If an experiment tested two variables at the same time, would the findings of the experiment be reliable? Explain.
126. Give two examples of what could cause scientists to change a hypothesis or theory they have formulated.
127. Can you think of any tools or technologies that might have developed from people’s observations of natural phenomena?
128. Describe a problem that was solved by development of a new technology and the steps of the solution process.
7th Grade - Chapter 1 ONLINE REVIEW
Answer Section
TRUE/FALSE
1. ANS: T PTS: 1 DIF: Webb's II OBJ: 1/1
STA: SC.H.1.3.1 SC.H.1.3.2
2. ANS: F PTS: 1 DIF: Webb's II OBJ: 4/2
STA: SC.H.1.3.3 SC.H.3.3.7
3. ANS: F PTS: 1 DIF: Webb's II OBJ: 3/2
STA: SC.H.1.3.1 SC.H.1.3.5 SC.H.1.3.7
4. ANS: T PTS: 1 DIF: Webb's I OBJ: 6/3
STA: SC.H.1.3.6 SC.H.3.3.5
5. ANS: F PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.H.1.3.1 SC.H.1.3.3
6. ANS: F PTS: 1 DIF: Webb's I OBJ: 4/2
STA: SC.H.1.3.3 SC.H.1.3.4 SC.H.1.3.7
7. ANS: T PTS: 1 DIF: Webb's I OBJ: 1/1
STA: SC.H.1.3.1 SC.H.1.3.5 SC.H.1.3.7
8. ANS: T PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.H.1.3.4 SC.H.1.3.5
9. ANS: F PTS: 1 DIF: Webb's II OBJ: 3/2
STA: SC.H.1.3.3
10. ANS: F PTS: 1 DIF: Webb's II OBJ: 4/2
STA: SC.H.1.3.3
11. ANS: T PTS: 1 DIF: Webb's I OBJ: 6/3
STA: SC.H.3.3.6 SC.H.3.3.7
12. ANS: F PTS: 1
13. ANS: F PTS: 1
14. ANS: F PTS: 1
15. ANS: F PTS: 1
16. ANS: T PTS: 1
MULTIPLE CHOICE
17. ANS: D PTS: 1 DIF: Webb's I STA: SC.H.1.3.3
18. ANS: A PTS: 1 DIF: Webb's I STA: SC.H.1.3.3
19. ANS: B PTS: 1 DIF: Webb's II STA: SC.H.1.3.3
20. ANS: C PTS: 1 DIF: Webb's I STA: SC.H.1.3.4
21. ANS: A PTS: 1 DIF: Webb's II STA: SC.H.1.3.5
22. ANS: B PTS: 1 DIF: Webb's II STA: SC.H.1.3.4
23. ANS: D PTS: 1 DIF: Webb's I STA: SC.H.1.3.1 SC.H.1.3.2
24. ANS: C PTS: 1 DIF: Webb's I STA: SC.H.1.3.2 SC.H.1.3.4
25. ANS: D PTS: 1 DIF: Webb's II STA: SC.H.1.3.5
26. ANS: B PTS: 1 DIF: Webb's II STA: SC.H.1.3.4
27. ANS: D PTS: 1 DIF: Webb's II STA: SC.H.1.3.2
28. ANS: A PTS: 1 DIF: Webb's II STA: SC.H.1.3.4
29. ANS: B PTS: 1 DIF: Webb's II STA: SC.H.3.3.4
30. ANS: B PTS: 1 DIF: Webb's II OBJ: 1/1
STA: SC.H.1.3.1
31. ANS: A PTS: 1 DIF: Webb's I OBJ: 5/3
STA: SC.H.3.3.7
32. ANS: D PTS: 1 DIF: Webb's I OBJ: 2/1
STA: SC.H.1.3.4
33. ANS: C PTS: 1 DIF: Webb's I OBJ: 2/1
STA: SC.H.1.3.4 SC.H.3.3.6
34. ANS: B PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.H.1.3.4
35. ANS: C PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.H.1.3.4
36. ANS: A PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.H.1.3.4
37. ANS: C PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.H.1.3.3
38. ANS: D PTS: 1 DIF: Webb's I OBJ: 3/2
39. ANS: B PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.H.1.3.5
40. ANS: C PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.H.1.3.5 SC.H.1.3.7
41. ANS: A PTS: 1 DIF: Webb's I OBJ: 4/2
STA: SC.H.1.3.4
42. ANS: D PTS: 1 DIF: Webb's I OBJ: 5/3
STA: SC.H.3.3.7
43. ANS: B PTS: 1 DIF: Webb's I OBJ: 4/2
STA: SC.H.1.3.4
44. ANS: A PTS: 1 DIF: Webb's I OBJ: 4/2
STA: SC.H.1.3.4
45. ANS: C PTS: 1 DIF: Webb's I OBJ: 4/2
COMPLETION
46. ANS: technology
PTS: 1
47. ANS: hypothesis
PTS: 1
48. ANS: measurement
PTS: 1
49. ANS: control
PTS: 1
50. ANS: random sample
PTS: 1
51. ANS: variable
PTS: 1
52. ANS: science
PTS: 1
53. ANS: data table
PTS: 1
54. ANS: observations and experiments
PTS: 1
55. ANS: several
PTS: 1
56. ANS: Identifying the problem
PTS: 1
57. ANS: technology
PTS: 1
58. ANS: define a problem
PTS: 1
MATCHING
59. ANS: F PTS: 1 DIF: Webb's I OBJ: 5/3
STA: SC.H.1.3.3
60. ANS: C PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.H.1.3.5
61. ANS: G PTS: 1 DIF: Webb's I OBJ: 6/3
STA: SC.H.3.3.6
62. ANS: D PTS: 1 DIF: Webb's I OBJ: 4/2
63. ANS: A PTS: 1 DIF: Webb's I OBJ: 3/2
64. ANS: B PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.H.1.3.5
65. ANS: E PTS: 1 DIF: Webb's I OBJ: 1/1
STA: SC.H.1.3.3
66. ANS: A PTS: 1 DIF: Webb's I OBJ: 2/1
STA: SC.H.1.3.4
67. ANS: B PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.H.1.3.4
68. ANS: B PTS: 1 DIF: Webb's I OBJ: 3/2
69. ANS: A PTS: 1 DIF: Webb's I OBJ: 2/1
STA: SC.H.1.3.4
70. ANS: A PTS: 1 DIF: Webb's I OBJ: 2/1
71. ANS: B PTS: 1 DIF: Webb's I OBJ: 3/2
72. ANS: B PTS: 1 DIF: Webb's I OBJ: 3/2
73. ANS: B PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.H.1.3.4
74. ANS: A PTS: 1 DIF: Webb's I OBJ: 2/1
STA: SC.H.1.3.4
75. ANS: C PTS: 1
76. ANS: D PTS: 1
77. ANS: E PTS: 1
78. ANS: L PTS: 1
79. ANS: I PTS: 1
80. ANS: J PTS: 1
81. ANS: K PTS: 1
82. ANS: A PTS: 1
83. ANS: B PTS: 1
84. ANS: G PTS: 1
85. ANS: D PTS: 1
86. ANS: E PTS: 1
87. ANS: E PTS: 1
88. ANS: B PTS: 1
89. ANS: A PTS: 1
SHORT ANSWER
90. ANS:
Following the same general steps when designing and conducting experiments helps to form a universal language and method for all scientists around the world to follow. This will help when scientists need to repeat experiments and use data from other scientists’ experiments to conduct their own studies.
PTS: 1 DIF: Webb's II STA: SC.H.1.3.4 SC.H.1.3.6
91. ANS:
Part A Scientific investigations should have only one independent variable so that any data can be attributed to that independent variable. With two variables, it would be difficult to explain the results of the experiment. One variable makes it easy to analyze the data and communicate the results.
Part B Dana’s lab partner would follow the detailed written plan of her experiment. This type of plan allows for other scientists to verify a researcher’s results by repeating the experiment themselves.
PTS: 1 DIF: Webb's III STA: SC.H.1.3.5
92. ANS:
Answers may include: it gives scientists a common language; multiplying and dividing by 10 makes calculations easy to use; prefixes used with units change them to larger or smaller units.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.H.1.3.4
93. ANS:
Answers may include: the data will be organized from the start; you will save time by not having to rewrite the data in a table; you will know that you have all the data you need to accurately analyze the results of the experiment.
PTS: 1 DIF: Webb's II OBJ: 4/2 STA: SC.H.1.3.4
94. ANS:
written reports and verbal presentations
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.H.3.3.6
95. ANS:
Answers may include: movies on large screens; movies on TV; videotaped movies; DVD movies on computer monitors.
PTS: 1 DIF: Webb's II OBJ: 5/3 STA: SC.H.3.3.7
96. ANS:
They may use cellular phones and computers to contact other scientists.
PTS: 1 DIF: Webb's II OBJ: 6/3 STA: SC.H.3.3.7
97. ANS:
Both have a problem to solve; both look for clues that they use to solve that problem.
PTS: 1 DIF: Webb's II OBJ: 1/1 STA: SC.H.1.3.2 SC.H.1.3.3
98. ANS:
Prior knowledge is used to make predictions about the results of an experiment. These predictions can be stated as the hypothesis.
PTS: 1 DIF: Webb's II OBJ: 1/1
99. ANS:
Answers may include: information about finding useful resources (books, magazines, etc.) can be found; internet links or web pages can be found; data can be analyzed; data can be displayed in graphics.
PTS: 1 DIF: Webb's II OBJ: 2/1 STA: SC.H.3.3.7
100. ANS:
Answers may include: observation, classification, interpretation of data, making measurements, comparing and contrasting.
PTS: 1 DIF: Webb's II OBJ: 2/1 STA: SC.H.1.3.4
101. ANS:
Answers may include: descriptions of their observations, mathematical measurements or formulas, step-by-step descriptions of procedures, listings of materials, drawings of equipment setups, specific results (data), questions that come up during experiments, problems that occur and possible solutions, other observations, etc.
PTS: 1 DIF: Webb's II OBJ: 2/1 STA: SC.H.1.3.3 SC.H.1.3.4
102. ANS:
recognize the problem, form a hypothesis, test your hypothesis, analyze the data, draw conclusions
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.H.1.3.4
103. ANS:
They might break the problem into smaller problems and decide which of those needs to be solved first. Different scientists might work on different aspects of a problem.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.H.1.3.3
104. ANS:
Answers may include: a map to locate the source of a cholera epidemic; a map of the spread of the spruce beetle; three-dimensional models of microscopic bacterium or a huge asteroid; design safer airplanes or buildings; testing ideas that would be too expensive to test other ways.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.H.3.3.7
105. ANS:
Answers may include: prior knowledge; science literature at the library; World Wide Web; computer disks or CDs.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.H.1.3.4 SC.H.1.3.5
106. ANS:
Answers may include: use a control; limit the number of variables being tested; conduct enough trials to get sufficient data; use proper materials and tools; eliminate bias; prepare good data tables.
PTS: 1 DIF: Webb's II OBJ: 4/2 STA: SC.H.1.3.4 SC.H.1.3.5
107. ANS:
time, cost, availability of materials, amount of space to set up trials
PTS: 1 DIF: Webb's II OBJ: 4/2
108. ANS:
different interpretations of verbal descriptors—to avoid this use numerical measurements; biased samples—use random samples
PTS: 1 DIF: Webb's II OBJ: 4/2 STA: SC.H.1.3.4
109. ANS:
Yes, it is just as important to learn that your hypothesis was incorrect as it is to learn that your hypothesis was correct. [There is also the possibility that even though the hypothesis was not supported in one experiment, it might still be correct. This is not actually stated in the text, but it is implied in the discussion of multiple trials and reliability.]
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.H.1.3.2 SC.H.1.3.7
110. ANS:
Answers may include: satellite tracking systems in cars; instruments that doctors can use to operate on unborn children; skin patch to release medicine into a person's system.
PTS: 1 DIF: Webb's II OBJ: 5/3 STA: SC.H.3.3.7
111. ANS:
No. Discoveries can be made by almost anyone—young or old, people pursuing a hobby, people of different sexes, races, cultures, etc.
PTS: 1 DIF: Webb's II OBJ: 6/3 STA: SC.H.1.3.6 SC.H.3.3.5
112. ANS:
New information can show that the old way of thinking or doing things is incorrect. For example, new discoveries may not fit in a current classification scheme. New models or new methods for doing things can be created to fit the current information. These new ways are also subject to change based on possible future discoveries.
PTS: 1 DIF: Webb's II OBJ: 5/3 STA: SC.H.1.3.1 SC.H.1.3.2
113. ANS:
Scientific information can be good or harmful, moral or immoral. People must decide if the information is used to help or harm people. Science cannot make that decision.
PTS: 1 DIF: Webb's III OBJ: 5/3 STA: SC.H.3.3.4
114. ANS:
Antibiotic 2 is more effective (fewer bacteria were still alive at the end of the experiment in Figure 1-1). Culture E serves as a control.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.H.1.3.3 SC.H.1.3.4
115. ANS:
c, d, a, b, f, e
PTS: 1
116. ANS:
New discoveries lead to new products that people can use every day. Examples of new products include movies, videotapes, DVDs, medicines, and satellite tracking systems.
PTS: 1
117. ANS:
Data may be recorded or summarized in the form of tables, charts, graphs, or written text.
PTS: 1
118. ANS:
You could place equal amounts of water and one thermometer in each beaker. Then place one beaker on each hot plate. Add salt to only one beaker. Heat both beakers until the water boils, then check the temperature for the boiling point of each. Compare the boiling point of the water alone to that of the water with salt added. Repeat with several trials to verify results.
PTS: 1
119. ANS:
1. problem
2. hypothesis
3. variables
4. controls
5. analyze
6. conclusions
PTS: 1
120. ANS:
Science is a way or process to investigate what is happening around us. Technology is the application of science to make products or tools that people can use.
PTS: 1
121. ANS:
Answers will vary depending on object, but should include defining its need, a scientific discovery on which the object is based, and how it was made into a product.
PTS: 1
122. ANS:
As an artifact, each of the individual components (computer, modem, transmission lines) are all hardware technology. As a technique, it is a new means of communication. As a social-technical system, it has changed how people interact with each other.
PTS: 1
123. ANS:
Define the problem, search for solutions, engineering production, test the model, produce the product.
PTS: 1
124. ANS:
It allows scientists from all over the world to understand each other’s work. And, since the units are based on units of ten, multiplication and division are easy to do.
PTS: 1
ESSAY
125. ANS:
No, because it would be impossible to tell which variable had caused the effect observed. Only one variable at a time can be changed.
PTS: 1
126. ANS:
Answers will vary: An experiment might call the hypothesis into question, or new information might be learned.
PTS: 1
127. ANS:
Answers will vary. May include: medicines, maps, thermometers, telescopes; microscopes. Accept all reasonable answers.
PTS: 1
128. ANS:
Answers will vary depending on the problem described, but should include: a definition of the problem, a proposed solution, how the concept was tested, and final product.
PTS: 1
True/False
Indicate whether the statement is true or false.
____ 1. Science has been used throughout history to answer questions about the world.
____ 2. Using a computer graphic is the only effective way to display the data from an experiment.
____ 3. If the results of your experiment do not support your hypothesis, it means that your hypothesis was wrong.
____ 4. Scientific discoveries have been made by people of different races, sexes, cultures, and time periods.
____ 5. There is usually only one correct method that can be used to solve a problem.
____ 6. The number of trials conducted is the same in every experiment.
____ 7. If the results of experiments do not support a prediction, scientists change their predictions.
____ 8. Because the quality of the solution to a problem depends on how well the entire project is carried out, planning is a very important step in science.
____ 9. Although a model was useful for locating the source of an 1871 cholera epidemic, models are rarely useful to scientists trying to solve other problems.
____ 10. Good experiments can only be conducted if you have the latest materials and tools.
____ 11. Modern electronic communications allow people throughout the world to learn quickly about new discoveries.
____ 12. A hypothesis is a statement of fact.
____ 13. Scientific discoveries are made only by professional scientists.
____ 14. Scientific discoveries influence only areas related to our health.
____ 15. Any information gathered from the Internet can be assumed to be accurate.
____ 16. The more trials you can run in an experiment, the more reliable the results.
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____ 17. What is the name for the steps scientists go through to solve problems?
a.
drawing conclusions
b.
forming a hypothesis
c.
research design
d.
scientific method
____ 18. Rita wants to study the history of her town. What type of research will she have to do?
a.
descriptive research
b.
experimental research
c.
research design
d.
variable research
____ 19. Why is a microscope considered technology?
a.
It uses electricity and has lenses.
b.
It uses a technique that helps solve a problem.
c.
Some people use it every day.
d.
It enables people to see details inside cells.
____ 20. How might a scientist show bias in an experiment?
a.
by asking others to verify the data
b.
by choosing a random sample by computer
c.
by drawing conclusions without analyzing data
d.
by using multiple trials to confirm data
____ 21. Mike is testing the effects of friction on a toy car going down a ramp. He runs one trial with sandpaper on the ramp and another trial with cloth on the ramp. What else does he need in his experiment?
a.
a control group
b.
a longer ramp
c.
an independent variable
d.
a technology
____ 22. Margo recorded data for her experiment on a line graph.
What conclusions can she draw from her data?
a.
Growth declined steadily each week.
b.
Growth increased steadily each week.
c.
A growth pattern cannot be determined.
d.
Growth will probably stop soon.
____ 23. What happens after a technological design process is tested successfully?
a.
Design flaws are identified.
b.
The new process is tested with the public.
c.
The constraints are listed.
d.
A pilot plant can be built.
____ 24. Which of the following is NOT a step in the scientific method?
a.
analyze your data
b.
communicate your results
c.
find your biases
d.
test your hypothesis
____ 25. Mike is conducting an experiment to see if his dog will eat a new brand of dog food. He will replace the dog’s old food with the new brand. Identify the dependent variable in this experiment.
a.
the amount of food
b.
the place the food is left
c.
the type of food
d.
whether the dog eats
____ 26. Why is it important for scientists to present their findings to the public?
a.
The public has to understand every scientific finding.
b.
Scientific data can benefit society in different ways.
c.
The scientist might be able to get the data published.
d.
The scientist needs credit for his or her findings.
____ 27. What is the best way to predict when the next full moon will occur?
a.
Collect data about the time of the sunset each day.
b.
Design an engineering experiment.
c.
Draw your own conclusion.
d.
Make a model of the solar system.
____ 28. Clara is conducting an experiment to find out the number of times her lab mice received a reward for finishing a task. She is using a tally chart to keep track of each mouse and the number of rewards each receives.
What is the best type of graph for her to use to analyze her data?
a.
bar graph
b.
line graph
c.
pictograph
d.
pie graph
____ 29. How does engineering meet human needs?
a.
It uses newly designed products.
b.
It solves problems.
c.
It uses technology.
d.
It uses science.
____ 30. Scientists use prior experience to ____.
a.
collect data
b.
make predictions about what will happen under certain circumstances
c.
analyze their data
d.
serve as a control in their experiments
____ 31. One example of technology that is commonly used by scientists is ____.
a.
computers
c.
variables
b.
hypotheses
d.
observations
____ 32. Examples of the skills used in science include ____ and ____.
a.
cholera , E. coli outbreaks
c.
facts , inferences
b.
clues , detectives
d.
observations , measurements
____ 33. After scientists analyze the results of their experiments, they ____.
a.
form hypotheses
b.
include a control
c.
communicate those results to other people
d.
choose the variables they want to test
____ 34. Which of the following steps to solve a problem must be completed first?
a.
analyzing data
c.
forming a hypothesis
b.
recognizing and identifying the problem
d.
testing a hypothesis
____ 35. Which of the following steps to solve a problem is completed last?
a.
analyzing data
c.
drawing conclusions
b.
recognizing and identifying the problem
d.
testing a hypothesis
____ 36. Listing what is known about a problem and possible ways to solve the problem are parts of ____.
a.
making a plan
c.
testing a hypothesis
b.
drawing conclusions
d.
eliminating bias
____ 37. ____ can save time and money by testing ideas that would otherwise be difficult to test quickly or easily.
a.
Biases
c.
Models
b.
Conclusions
d.
Variables
____ 38. A prediction or statement that can be tested is ____.
a.
a conclusion
c.
a control
b.
an observation
d.
a hypothesis
____ 39. A factor in an experiment that can change is ____.
a.
an observation
c.
a control
b.
a variable
d.
a hypothesis
____ 40. A sample that is treated exactly like the other experimental groups except that the variable is not applied to it is a(n) ____.
a.
observation
c.
control
b.
variable
d.
hypothesis
____ 41. Scientists conduct multiple trials of their experiments because ____.
a.
their results are more likely to be reliable
b.
it costs less to run more trials than fewer trials
c.
unusual occurrences are likely to be repeated every time
d.
experiments always have the same results
____ 42. One tool that can be used to display your data is a ____.
a.
balance
c.
microscope
b.
spring scale
d.
computer
____ 43. One way to reduce bias in an experiment is to ____.
a.
ask only girls a question about a school topic
b.
take numerical measurements of the results
c.
use descriptive phrases as your data
d.
make sure that the results come out the way you want them
____ 44. A good way to organize and record your results and observations is ____.
a.
in a data table
b.
by using a calculator
c.
with a balance or spring scale
d.
by having a hypothesis before you begin your experiment
____ 45. Which of the following units is part of the International System of Units, or SI?
a.
pounds
c.
meters
b.
ounces
d.
inches
Completion
Complete each statement.
46. use of knowledge to make products or tools ____________________
47. a prediction or statement that can be tested tools ____________________
48. SI is used for this purpose ____________________
49. sample treated like other experimental groups except no variable is used ____________________
50. sample taken without bias ____________________
51. a factor in an experiment that can change ____________________
52. a way or a process to investigate what is happening around us ____________________
53. way to organize and record results and observations ____________________
Correctly complete each sentence by choosing the best choice in parentheses.
54. Scientists use ______________________________ (observations, experiments, observations and experiments) to find answers to questions.
55. In today’s society, there is/are usually ____________________ (only one, a pair of, several) scientist[s] working on a problem at one time.
56. _________________________ (Making a detailed plan, Making a model, Identifying the problem) is the first step a scientist would take to solve a problem.
57. New artifacts, new techniques, and new social-technical systems are types of ____________________ (scientific discovery, technology, engineering advances).
58. The first step in finding a scientific solution to a problem or human need is ____________________ (make a discovery, define a problem, test a model).
Matching
Match each term with its description below.
a.
hypothesis
e.
science
b.
variable
f.
technology
c.
control
g.
globalization
d.
SI
____ 59. use of knowledge to make products or tools that people can use
____ 60. a sample that is treated exactly like the other experimental groups except that the variable is not applied to it
____ 61. worldwide distribution
____ 62. a system of units used by scientists that is based on units of ten
____ 63. a prediction or statement that can be tested
____ 64. a factor in an experiment that can change
____ 65. a process used to solve a problem
Match a or b to each term below.
a.
general skill used in science
b.
specific step scientists follow to solve problems
____ 66. observing
____ 67. analyzing data
____ 68. forming a hypothesis
____ 69. comparing and contrasting
____ 70. classifying
____ 71. drawing conclusions
____ 72. recognizing the problem
____ 73. testing a hypothesis
____ 74. measuring
Match the description with the correct term. Some items may not be used.
a.
model
g.
control
b.
random
h.
scientist
c.
data table
i.
hypothesis
d.
trial
j.
bias
e.
technology
k.
variable
f.
science log
l.
science
____ 75. a way to record results and observations accurately
____ 76. a single run of an experiment
____ 77. the application of science to make products or tools
____ 78. a way or a process to investigate what is happening around us
____ 79. a prediction or statement that can be tested
____ 80. a slanted view
____ 81. a factor that can change in an experiment
____ 82. used to represent things that happen too slowly or quickly t observe directly
____ 83. a type of sample taken without bias
____ 84. sample treated like other experimental groups except no viable is used
Match the following SI units with what they measure.
a.
temperature
d.
length
b.
liquid volume
e.
mass
c.
area
____ 85. meter
____ 86. gram
____ 87. tonne
____ 88. liter
____ 89. degrees Celsius
Short Answer
90.
Why is it important for all scientists to follow the same general steps when doing scientific investigations?
91.
Dana writes a detailed plan for a scientific investigation. First she shows her plan to her lab partner. He advises that she should use only one independent variable instead of two. She then rewrites her plan to incorporate his comments, and she conducts the experiment.
Part A Why do you think Dana’s lab partner advises against two independent variables in her experiment?
Part B If Dana’s lab partner wants to repeat the experiment, how would he do so?
92.
Give at least two reasons why scientists use the International System of Units (SI).
93.
List at least two reasons for designing your data tables before beginning your experiment.
94.
What are two ways that scientists communicate their results to other people?
95.
List three examples of how technology has made entertainment more accessible to people over the last one hundred years.
96.
Describe how scientists around the world use technology to discuss their results.
97.
How is the work of scientists similar to the work of detectives?
98.
Describe how prior knowledge may be used by scientists.
99.
List three ways that computers can be used in research.
100.
List at least four skills that scientists commonly use.
101.
List at least four types of information that scientists might include in a journal.
102.
Sequence the following steps: test your hypothesis, draw conclusions, recognize the problem, analyze the data, form a hypothesis.
103.
How might scientists go about trying to solve a large, complicated problem?
104.
Give an example of how scientists might use a computer model.
105.
List at least two possible sources of information that you could use to form a hypothesis.
106.
List at least three things you should be careful to do when designing an experiment.
107.
What are at least two factors that might influence the decision about how many trials of an experiment to conduct?
108.
State at least one possible source of bias in an experiment and describe how you can reduce it.
109.
If the results of your experiment do not support your hypothesis, have you still learned something important? Explain.
110.
Besides advances in the entertainment industry, give an example of how technology could make a difference in your everyday life.
111.
Are all scientific discoveries made by professional scientists? Explain.
112.
Describe how new scientific knowledge can challenge old ways of thinking or doing things.
113.
Is all scientific information good? Can some information be harmful? Can science make these decisions?
Figure 1-1
114.
An experiment was conducted to test which of two antibiotics was more effective at killing a certain type of bacterium. Cultures A and B were treated with antibiotic 1; cultures C and D were treated with antibiotic 2; culture E was not treated with any antibiotic. Based on the results shown in Figure 1-1, what conclusion would you draw about which antibiotic is more effective? Explain. What is the purpose of culture E?
115. Number these steps for doing an experiment in the correct order.
a. Test your hypothesis.
b. Analyze your data.
c. Recognize the problem.
d. Form a hypothesis.
e. Communicate your results.
f. Draw conclusions.
116. How do new scientific discoveries affect our everyday life? Give examples.
117. What are some ways that data can be recorded in a science journal?
118. How could you use two beakers, distilled water, two hot plates, two thermometers, and salt to test if adding salt affects the boiling point of water?
119. Complete the following events chain for doing experimental research.
1. Recognize the _________________.
¯
2. Form a ______________________.
¯
3. Select dependent and independent
___________________
รง
Run multiple trials of experiment
¯
4. Identify _____________________.
¯
5. ___________________ your results.
¯
6. Draw ______________________.
¯
communicate
120. Compare and contrast science and technology.
121. Choose an object that you use every day. Explain how science and technology were applied to its development.
122. Explain how the Internet or its parts could be described as an artifact, a technique, and as a social-technical system.
123. What are the main steps of solving a scientific problem?
124. Discuss two advantages of using the International System of Units, or SI, for measurements in scientific research.
Essay
125. If an experiment tested two variables at the same time, would the findings of the experiment be reliable? Explain.
126. Give two examples of what could cause scientists to change a hypothesis or theory they have formulated.
127. Can you think of any tools or technologies that might have developed from people’s observations of natural phenomena?
128. Describe a problem that was solved by development of a new technology and the steps of the solution process.
7th Grade - Chapter 1 ONLINE REVIEW
Answer Section
TRUE/FALSE
1. ANS: T PTS: 1 DIF: Webb's II OBJ: 1/1
STA: SC.H.1.3.1 SC.H.1.3.2
2. ANS: F PTS: 1 DIF: Webb's II OBJ: 4/2
STA: SC.H.1.3.3 SC.H.3.3.7
3. ANS: F PTS: 1 DIF: Webb's II OBJ: 3/2
STA: SC.H.1.3.1 SC.H.1.3.5 SC.H.1.3.7
4. ANS: T PTS: 1 DIF: Webb's I OBJ: 6/3
STA: SC.H.1.3.6 SC.H.3.3.5
5. ANS: F PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.H.1.3.1 SC.H.1.3.3
6. ANS: F PTS: 1 DIF: Webb's I OBJ: 4/2
STA: SC.H.1.3.3 SC.H.1.3.4 SC.H.1.3.7
7. ANS: T PTS: 1 DIF: Webb's I OBJ: 1/1
STA: SC.H.1.3.1 SC.H.1.3.5 SC.H.1.3.7
8. ANS: T PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.H.1.3.4 SC.H.1.3.5
9. ANS: F PTS: 1 DIF: Webb's II OBJ: 3/2
STA: SC.H.1.3.3
10. ANS: F PTS: 1 DIF: Webb's II OBJ: 4/2
STA: SC.H.1.3.3
11. ANS: T PTS: 1 DIF: Webb's I OBJ: 6/3
STA: SC.H.3.3.6 SC.H.3.3.7
12. ANS: F PTS: 1
13. ANS: F PTS: 1
14. ANS: F PTS: 1
15. ANS: F PTS: 1
16. ANS: T PTS: 1
MULTIPLE CHOICE
17. ANS: D PTS: 1 DIF: Webb's I STA: SC.H.1.3.3
18. ANS: A PTS: 1 DIF: Webb's I STA: SC.H.1.3.3
19. ANS: B PTS: 1 DIF: Webb's II STA: SC.H.1.3.3
20. ANS: C PTS: 1 DIF: Webb's I STA: SC.H.1.3.4
21. ANS: A PTS: 1 DIF: Webb's II STA: SC.H.1.3.5
22. ANS: B PTS: 1 DIF: Webb's II STA: SC.H.1.3.4
23. ANS: D PTS: 1 DIF: Webb's I STA: SC.H.1.3.1 SC.H.1.3.2
24. ANS: C PTS: 1 DIF: Webb's I STA: SC.H.1.3.2 SC.H.1.3.4
25. ANS: D PTS: 1 DIF: Webb's II STA: SC.H.1.3.5
26. ANS: B PTS: 1 DIF: Webb's II STA: SC.H.1.3.4
27. ANS: D PTS: 1 DIF: Webb's II STA: SC.H.1.3.2
28. ANS: A PTS: 1 DIF: Webb's II STA: SC.H.1.3.4
29. ANS: B PTS: 1 DIF: Webb's II STA: SC.H.3.3.4
30. ANS: B PTS: 1 DIF: Webb's II OBJ: 1/1
STA: SC.H.1.3.1
31. ANS: A PTS: 1 DIF: Webb's I OBJ: 5/3
STA: SC.H.3.3.7
32. ANS: D PTS: 1 DIF: Webb's I OBJ: 2/1
STA: SC.H.1.3.4
33. ANS: C PTS: 1 DIF: Webb's I OBJ: 2/1
STA: SC.H.1.3.4 SC.H.3.3.6
34. ANS: B PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.H.1.3.4
35. ANS: C PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.H.1.3.4
36. ANS: A PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.H.1.3.4
37. ANS: C PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.H.1.3.3
38. ANS: D PTS: 1 DIF: Webb's I OBJ: 3/2
39. ANS: B PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.H.1.3.5
40. ANS: C PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.H.1.3.5 SC.H.1.3.7
41. ANS: A PTS: 1 DIF: Webb's I OBJ: 4/2
STA: SC.H.1.3.4
42. ANS: D PTS: 1 DIF: Webb's I OBJ: 5/3
STA: SC.H.3.3.7
43. ANS: B PTS: 1 DIF: Webb's I OBJ: 4/2
STA: SC.H.1.3.4
44. ANS: A PTS: 1 DIF: Webb's I OBJ: 4/2
STA: SC.H.1.3.4
45. ANS: C PTS: 1 DIF: Webb's I OBJ: 4/2
COMPLETION
46. ANS: technology
PTS: 1
47. ANS: hypothesis
PTS: 1
48. ANS: measurement
PTS: 1
49. ANS: control
PTS: 1
50. ANS: random sample
PTS: 1
51. ANS: variable
PTS: 1
52. ANS: science
PTS: 1
53. ANS: data table
PTS: 1
54. ANS: observations and experiments
PTS: 1
55. ANS: several
PTS: 1
56. ANS: Identifying the problem
PTS: 1
57. ANS: technology
PTS: 1
58. ANS: define a problem
PTS: 1
MATCHING
59. ANS: F PTS: 1 DIF: Webb's I OBJ: 5/3
STA: SC.H.1.3.3
60. ANS: C PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.H.1.3.5
61. ANS: G PTS: 1 DIF: Webb's I OBJ: 6/3
STA: SC.H.3.3.6
62. ANS: D PTS: 1 DIF: Webb's I OBJ: 4/2
63. ANS: A PTS: 1 DIF: Webb's I OBJ: 3/2
64. ANS: B PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.H.1.3.5
65. ANS: E PTS: 1 DIF: Webb's I OBJ: 1/1
STA: SC.H.1.3.3
66. ANS: A PTS: 1 DIF: Webb's I OBJ: 2/1
STA: SC.H.1.3.4
67. ANS: B PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.H.1.3.4
68. ANS: B PTS: 1 DIF: Webb's I OBJ: 3/2
69. ANS: A PTS: 1 DIF: Webb's I OBJ: 2/1
STA: SC.H.1.3.4
70. ANS: A PTS: 1 DIF: Webb's I OBJ: 2/1
71. ANS: B PTS: 1 DIF: Webb's I OBJ: 3/2
72. ANS: B PTS: 1 DIF: Webb's I OBJ: 3/2
73. ANS: B PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.H.1.3.4
74. ANS: A PTS: 1 DIF: Webb's I OBJ: 2/1
STA: SC.H.1.3.4
75. ANS: C PTS: 1
76. ANS: D PTS: 1
77. ANS: E PTS: 1
78. ANS: L PTS: 1
79. ANS: I PTS: 1
80. ANS: J PTS: 1
81. ANS: K PTS: 1
82. ANS: A PTS: 1
83. ANS: B PTS: 1
84. ANS: G PTS: 1
85. ANS: D PTS: 1
86. ANS: E PTS: 1
87. ANS: E PTS: 1
88. ANS: B PTS: 1
89. ANS: A PTS: 1
SHORT ANSWER
90. ANS:
Following the same general steps when designing and conducting experiments helps to form a universal language and method for all scientists around the world to follow. This will help when scientists need to repeat experiments and use data from other scientists’ experiments to conduct their own studies.
PTS: 1 DIF: Webb's II STA: SC.H.1.3.4 SC.H.1.3.6
91. ANS:
Part A Scientific investigations should have only one independent variable so that any data can be attributed to that independent variable. With two variables, it would be difficult to explain the results of the experiment. One variable makes it easy to analyze the data and communicate the results.
Part B Dana’s lab partner would follow the detailed written plan of her experiment. This type of plan allows for other scientists to verify a researcher’s results by repeating the experiment themselves.
PTS: 1 DIF: Webb's III STA: SC.H.1.3.5
92. ANS:
Answers may include: it gives scientists a common language; multiplying and dividing by 10 makes calculations easy to use; prefixes used with units change them to larger or smaller units.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.H.1.3.4
93. ANS:
Answers may include: the data will be organized from the start; you will save time by not having to rewrite the data in a table; you will know that you have all the data you need to accurately analyze the results of the experiment.
PTS: 1 DIF: Webb's II OBJ: 4/2 STA: SC.H.1.3.4
94. ANS:
written reports and verbal presentations
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.H.3.3.6
95. ANS:
Answers may include: movies on large screens; movies on TV; videotaped movies; DVD movies on computer monitors.
PTS: 1 DIF: Webb's II OBJ: 5/3 STA: SC.H.3.3.7
96. ANS:
They may use cellular phones and computers to contact other scientists.
PTS: 1 DIF: Webb's II OBJ: 6/3 STA: SC.H.3.3.7
97. ANS:
Both have a problem to solve; both look for clues that they use to solve that problem.
PTS: 1 DIF: Webb's II OBJ: 1/1 STA: SC.H.1.3.2 SC.H.1.3.3
98. ANS:
Prior knowledge is used to make predictions about the results of an experiment. These predictions can be stated as the hypothesis.
PTS: 1 DIF: Webb's II OBJ: 1/1
99. ANS:
Answers may include: information about finding useful resources (books, magazines, etc.) can be found; internet links or web pages can be found; data can be analyzed; data can be displayed in graphics.
PTS: 1 DIF: Webb's II OBJ: 2/1 STA: SC.H.3.3.7
100. ANS:
Answers may include: observation, classification, interpretation of data, making measurements, comparing and contrasting.
PTS: 1 DIF: Webb's II OBJ: 2/1 STA: SC.H.1.3.4
101. ANS:
Answers may include: descriptions of their observations, mathematical measurements or formulas, step-by-step descriptions of procedures, listings of materials, drawings of equipment setups, specific results (data), questions that come up during experiments, problems that occur and possible solutions, other observations, etc.
PTS: 1 DIF: Webb's II OBJ: 2/1 STA: SC.H.1.3.3 SC.H.1.3.4
102. ANS:
recognize the problem, form a hypothesis, test your hypothesis, analyze the data, draw conclusions
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.H.1.3.4
103. ANS:
They might break the problem into smaller problems and decide which of those needs to be solved first. Different scientists might work on different aspects of a problem.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.H.1.3.3
104. ANS:
Answers may include: a map to locate the source of a cholera epidemic; a map of the spread of the spruce beetle; three-dimensional models of microscopic bacterium or a huge asteroid; design safer airplanes or buildings; testing ideas that would be too expensive to test other ways.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.H.3.3.7
105. ANS:
Answers may include: prior knowledge; science literature at the library; World Wide Web; computer disks or CDs.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.H.1.3.4 SC.H.1.3.5
106. ANS:
Answers may include: use a control; limit the number of variables being tested; conduct enough trials to get sufficient data; use proper materials and tools; eliminate bias; prepare good data tables.
PTS: 1 DIF: Webb's II OBJ: 4/2 STA: SC.H.1.3.4 SC.H.1.3.5
107. ANS:
time, cost, availability of materials, amount of space to set up trials
PTS: 1 DIF: Webb's II OBJ: 4/2
108. ANS:
different interpretations of verbal descriptors—to avoid this use numerical measurements; biased samples—use random samples
PTS: 1 DIF: Webb's II OBJ: 4/2 STA: SC.H.1.3.4
109. ANS:
Yes, it is just as important to learn that your hypothesis was incorrect as it is to learn that your hypothesis was correct. [There is also the possibility that even though the hypothesis was not supported in one experiment, it might still be correct. This is not actually stated in the text, but it is implied in the discussion of multiple trials and reliability.]
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.H.1.3.2 SC.H.1.3.7
110. ANS:
Answers may include: satellite tracking systems in cars; instruments that doctors can use to operate on unborn children; skin patch to release medicine into a person's system.
PTS: 1 DIF: Webb's II OBJ: 5/3 STA: SC.H.3.3.7
111. ANS:
No. Discoveries can be made by almost anyone—young or old, people pursuing a hobby, people of different sexes, races, cultures, etc.
PTS: 1 DIF: Webb's II OBJ: 6/3 STA: SC.H.1.3.6 SC.H.3.3.5
112. ANS:
New information can show that the old way of thinking or doing things is incorrect. For example, new discoveries may not fit in a current classification scheme. New models or new methods for doing things can be created to fit the current information. These new ways are also subject to change based on possible future discoveries.
PTS: 1 DIF: Webb's II OBJ: 5/3 STA: SC.H.1.3.1 SC.H.1.3.2
113. ANS:
Scientific information can be good or harmful, moral or immoral. People must decide if the information is used to help or harm people. Science cannot make that decision.
PTS: 1 DIF: Webb's III OBJ: 5/3 STA: SC.H.3.3.4
114. ANS:
Antibiotic 2 is more effective (fewer bacteria were still alive at the end of the experiment in Figure 1-1). Culture E serves as a control.
PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.H.1.3.3 SC.H.1.3.4
115. ANS:
c, d, a, b, f, e
PTS: 1
116. ANS:
New discoveries lead to new products that people can use every day. Examples of new products include movies, videotapes, DVDs, medicines, and satellite tracking systems.
PTS: 1
117. ANS:
Data may be recorded or summarized in the form of tables, charts, graphs, or written text.
PTS: 1
118. ANS:
You could place equal amounts of water and one thermometer in each beaker. Then place one beaker on each hot plate. Add salt to only one beaker. Heat both beakers until the water boils, then check the temperature for the boiling point of each. Compare the boiling point of the water alone to that of the water with salt added. Repeat with several trials to verify results.
PTS: 1
119. ANS:
1. problem
2. hypothesis
3. variables
4. controls
5. analyze
6. conclusions
PTS: 1
120. ANS:
Science is a way or process to investigate what is happening around us. Technology is the application of science to make products or tools that people can use.
PTS: 1
121. ANS:
Answers will vary depending on object, but should include defining its need, a scientific discovery on which the object is based, and how it was made into a product.
PTS: 1
122. ANS:
As an artifact, each of the individual components (computer, modem, transmission lines) are all hardware technology. As a technique, it is a new means of communication. As a social-technical system, it has changed how people interact with each other.
PTS: 1
123. ANS:
Define the problem, search for solutions, engineering production, test the model, produce the product.
PTS: 1
124. ANS:
It allows scientists from all over the world to understand each other’s work. And, since the units are based on units of ten, multiplication and division are easy to do.
PTS: 1
ESSAY
125. ANS:
No, because it would be impossible to tell which variable had caused the effect observed. Only one variable at a time can be changed.
PTS: 1
126. ANS:
Answers will vary: An experiment might call the hypothesis into question, or new information might be learned.
PTS: 1
127. ANS:
Answers will vary. May include: medicines, maps, thermometers, telescopes; microscopes. Accept all reasonable answers.
PTS: 1
128. ANS:
Answers will vary depending on the problem described, but should include: a definition of the problem, a proposed solution, how the concept was tested, and final product.
PTS: 1
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