6th Grade - CHapter 16 ONLINE REVIEW

6th Grade - CHapter 16 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. When a substance burns, matter is destroyed. _________________________

____ 2. Elements on the far right of the periodic table are classified as nonmetals. _________________________

____ 3. Substances are either elements or mixtures. _________________________

____ 4. Thompson's experiments led to the discovery of the neutron. _________________________

____ 5. The closer an electron is to the nucleus, the lower its energy. _________________________

____ 6. Every atom of the same element has the same atomic number. _________________________

____ 7. For an atom to be neutral, the number of protons must equal the number of neutrons. _________________________

____ 8. Matter always has mass. _________________________

____ 9. Matter is anything that you can see and that takes up space. _________________________

____ 10. Metalloids are elements that have characteristics of both metals and nonmetals. _________________________

____ 11. J. J. Thomson’s experiments with cathode rays led to the discovery of the neutron. _________________________

____ 12. A compound with the formula C6H12O6 is made up of three atoms. _________________________

____ 13. Fruit salad is an example of a heterogeneous mixture. _________________________

Multiple Choice
Identify the choice that best completes the statement or answers the question.

____ 14. Kay is learning about an element that has 15 protons. Its mass number is 27. How many neutrons does it have?
a.
10
b.
12
c.
14
d.
42


____ 15. Cynthia looks at an illustration of a carbon dioxide molecule.
What is the formula for carbon dioxide?
a.
CO
b.
CO2
c.
OC2
d.
C20


____ 16. Which makes up more than 97 percent of your body?
a.
air
b.
carbon and hydrogen
c.
nonmetals
d.
water


____ 17. Stephen is writing a report about whether light is matter. Which should be his conclusion?
a.
No, because it does not take up space.
b.
No, because it has only a tiny amount of mass.
c.
Yes, because it is visible to the eye.
d.
Yes, because large amounts of it can be weighed.


____ 18. In chemical formulas of compounds, subscript numbers sometimes follow element symbols. What do these numbers represent?
a.
how many neutrons of that element exist in one unit of that compound
b.
how many atoms of that element exist in one unit of that compound
c.
the number of compounds that can be created with that particular element
d.
the number of elements that exist within that particular compound


____ 19. Roberta is drawing an atom for a class poster.
How many electrons did Roberta draw?
a.
1
b.
2
c.
3
d.
4


____ 20. Which is a particle that makes up most types of matter?
a.
atom
b.
element
c.
ether
d.
molecule


____ 21. Some matter has a positive charge, other matter has a negative charge. Which describes matter that has an equal amount of positive and negative charge?
a.
equal
b.
even
c.
neutral
d.
nucleus


____ 22. Tonya is preparing a presentation about atoms. She is particularly interested in the tiny particles that make up protons and neutrons. What are these particles?
a.
anodes
b.
cathodes
c.
electrons
d.
quarks


____ 23. Which is an example of a mixture?
a.
blood
b.
salt
c.
sugar
d.
water


____ 24. Why do scientists who study atoms often find it helpful to develop models of their theories?
a.
Models always show scientists that their theories must be correct.
b.
Models are difficult to develop and therefore difficult to disprove.
c.
Models are usually more complex than what is being studied.
d.
Models help them understand and explain things that cannot be seen.


____ 25. Which are uncharged particles?
a.
alpha particles
b.
neutrons
c.
nuclei
d.
protons


____ 26. Which of these combines to form all living and most nonliving things?
a.
electrons
b.
elements
c.
mixtures
d.
protons


____ 27. Matter that has the same composition and properties throughout is called a(n) ____.
a.
substance
c.
atom
b.
mixture
d.
isotope


____ 28. When two pure substances are combined so that each of the pure substances retains its own properties, the result is a(n) ____.
a.
compound
c.
element
b.
mixture
d.
isotope


____ 29. All ____ except mercury are solids at room temperature.
a.
metalloids
c.
metals
b.
nonmetals
d.
mixtures


____ 30. How many atoms of calcium are in a unit of calcium phosphate whose formula is Ca3(PO4)2?
a.
one
c.
three
b.
two
d.
four


____ 31. In general, nonmetals are ____.
a.
good conductors of electricity
c.
good conductors of heat
b.
malleable and ductile
d.
gases at room temperature


____ 32. In general, metals are ____.
a.
poor conductors of heat
c.
poor conductors of electricity
b.
brittle
d.
good conductors of heat


____ 33. When Rutherford performed his metal foil experiment, he was surprised that most of the alpha particles ____.
a.
were deflected by the foil
c.
were absorbed by the foil
b.
bounced back from the foil
d.
passed straight through the foil


____ 34. Water and hydrogen peroxide have different properties because ____.
a.
they are made from different elements
b.
one contains a greater percentage of oxygen than the other
c.
one is a compound and one is a mixture
d.
only water follows the law of definite proportions


____ 35. Which of these statements about matter is NOT true?
a.
During chemical changes, matter is destroyed.
b.
Matter has mass and takes up space.
c.
Matter can be divided into pure substances and mixtures.
d.
Matter is made up of atoms.


____ 36. The millions of compounds that exist are made from approximately ____ elements.
a.
50
c.
115
b.
75
d.
150


____ 37. Most of the mass of an atom is found in its ____.
a.
nucleus
c.
atomic number
b.
electron cloud
d.
mass number


____ 38. Vegetable soup is an example of a ____.
a.
homogeneous mixture
c.
compound
b.
heterogeneous mixture
d.
pure substance


____ 39. When someone stirs cocoa powder into hot water or hot milk, the cocoa changes from a ____.
a.
homogeneous mixture into a compound
b.
homogeneous mixture into a non-uniform mixture
c.
compound into a heterogeneous mixture
d.
heterogeneous mixture into a homogeneous mixture


____ 40. A certain atom has 26 protons, 26 electrons, and 30 neutrons. It mass number is ____.
a.
26
c.
52
b.
30
d.
56


____ 41. Which of the following CANNOT be classified as matter?
a.
an odorless, colorless gas
c.
alpha particles
b.
the heat given off by a light bulb
d.
an electron cloud


____ 42. ____ has mass and takes up space.
a.
Thought
c.
Air
b.
Light
d.
Emotion


____ 43. A(n) ____ is a particle in an atom with a positive charge.
a.
electron
c.
neutron
b.
isotope
d.
proton


____ 44. Each of these is an example of matter EXCEPT ____.
a.
a cloud
c.
a dust particle
b.
a beam of light
d.
air


____ 45. An atom of the element with atomic number 6 always has ____.
a.
six electron clouds
c.
six protons in its nucleus
b.
more than six neutrons
d.
an atomic mass of six


____ 46. The atomic number of an element tells the number of ____ in the nucleus of an atom of that element.
a.
neutrons
c.
protons
b.
electrons
d.
isotopes


____ 47. Rutherford’s experiment showed that most of an atom is made up of ____.
a.
an electron cloud
c.
alpha particles
b.
a nucleus
d.
empty space


____ 48. Isotopes of an element contain different numbers of ____.
a.
electrons
c.
protons
b.
neutrons
d.
energy levels


____ 49. Water is an example of a(n) ____.
a.
compound
c.
homogeneous mixture
b.
heterogeneous mixture
d.
element


____ 50. Most elements found on the left side of the periodic table are ____.
a.
metals
c.
brittle
b.
metalloids
d.
nonmetals


____ 51. Air is an example of a ____.
a.
heterogeneous mixture
c.
substance
b.
compound
d.
homogeneous mixture


____ 52. ____ developed a model called the atomic theory of matter.
a.
John Dalton
c.
Democritus
b.
Ernest Rutherford
d.
J. J. Thompson


____ 53. During Chadwick’s experiments, streams of ____ were unaffected by an electric field.
a.
alpha particles
c.
electrons
b.
neutrons
d.
protons


____ 54. ____ are small particles that make up most types of matter on Earth.
a.
Compounds
c.
Mixtures
b.
Elements
d.
Atoms


____ 55. Matter that is NOT considered to be a single substance is a(n) ____.
a.
compound
c.
mixture
b.
element
d.
isotope


____ 56. A property NOT associated with metals is ____.
a.
electric conductivity
c.
shininess
b.
ductility
d.
brittleness


Completion
Complete each statement.

57. All matter is made up of particles called ____________________.

58. If pure gold is classified as 24-karat gold, then 10-karat gold must be a ____________________ mixture.

59. Elements on the left side of the periodic table are classified as ____________________.

60. A pillowcase full of Halloween candy is a ____________________ mixture.

61. For material to be classified as a pure ____________________, every bit of it must have the same properties.

62. Elements that have properties halfway between those of metals and nonmetals, are classified as ____________________.

63. Rutherford's contribution to atomic models was the discovery of the ____________________.

64. Chlorine-35 and chlorine-37 are examples of ____________________.

65. Chlorine-35 and chlorine-37 have a different number of ____________________.

Choose the term in parentheses that correctly completes the sentence.

66. An element is made up of only one kind of ____________________ (isotope, atom, plastic).

67. The periodic table lists ____________________ (common molecules, compounds, elements).

68. Isotopes can have the same ____________________ (mass number, atomic number, number of subatomic particles).

69. Most elements are ____________________ (metals, nonmetals, metalloids).

70. On the periodic table, metalloids are found ____________________ (on the left side, on the right side, between the metals and nonmetals).

71. A ____________________ (metal, metalloid, nonmetal) has no luster and is a poor conductor.

72. Many ____________________ (metals, metalloids, nonmetals) can conduct heat and electricity, but they are not the best conductors.

73. The ____________________ (metals, metalloids, nonmetals) all are malleable, have luster, and are good conductors.

74. The elements in a ____________________ (mixture, solution, compound) are always combined in the same proportion by mass.

75. The compound ammonia contains three atoms of hydrogen for every atom of nitrogen, so the chemical formula for ammonia is ____________________ (NH3, N3H3, N3H).

76. An example of a homogeneous mixture is ____________________ (vegetable soup, air, granite rock).

77. A mixture is heterogeneous if ___________________________________ (it is made of two compounds, one of its parts is water, you can see its individual parts).

Matching

Match the drawings in Figure 3-1 to the descriptions below.

Figure 3-1

____ 78. element

____ 79. mixture of two elements

____ 80. compound

____ 81. mixture of two compounds

____ 82. mixture of a compound and element

Match each symbol or formula with the correct element or compound.
a.
O2
c.
CO
b.
CO2
d.
C


____ 83. carbon

____ 84. oxygen

____ 85. carbon monoxide

____ 86. carbon dioxide

Match each item with the correct description below.
a.
atom
j.
matter
b.
atomic mass
k.
metals
c.
atomic number
l.
metalloids
d.
compound
m.
mixtures
e.
electron
n.
neutron
f.
element
o.
nonmetals
g.
isotopes
p.
nucleus
h.
law of conservation of matter
q.
proton
i.
mass number
r.
substance


____ 87. weighted average mass of an element

____ 88. a sample of matter that has the same composition and properties throughout

____ 89. states that matter is neither created nor destroyed, only changed in form

____ 90. negatively charged subatomic particle

____ 91. positively charged central part of the atom

____ 92. positively charged particle in the nucleus of the atom

____ 93. uncharged particle in the nucleus of the atom

____ 94. elements that generally have a shiny or metallic luster

____ 95. matter made up of only one kind of atom

____ 96. tells you the number of protons in the nucleus of each atom of an element

____ 97. anything that has mass and takes up space

____ 98. atoms of the same element that have different numbers of neutrons

____ 99. the sum of an atom’s protons and neutrons

____ 100. a small particle that makes up most types of matter on Earth

____ 101. a pure substance whose smallest unit is made up of atoms of more than one element

____ 102. formed when two or more substances come together but don’t combine to form a new substance

____ 103. elements that are usually dull in appearance and poor conductors of heat and electricity

____ 104. elements that have characteristics of both metals and nonmetals

Short Answer

105.
Eric’s younger sister has learned that by pouring water into her sandbox she can build taller sand castles for her toys. One day as she plays in the sandbox with some toys, Eric brings her some lemonade to drink. What kind of mixtures are present?

106.
Juanita knows that elements fall into three categories: metals, metalloids, and nonmetals. She is examining two elements, both of which are solid and conduct heat. Element A is shiny, Element B is not. Into which category might these two elements fall? Explain your answer.

107.
Describe a method you could use to separate a mixture of sand and sugar.

108.
Is gasoline a compound, a homogenous mixture, or a heterogeneous mixture? (Keep in mind that hi-test gasoline has a higher octane level than regular gasoline.) Explain your answer.

109.
Suppose a freezer tray is filled with distilled water. If one of the ice cubes from the tray is placed in a glass of distilled water, how should the contents of the glass be classified?

110.
Scientists used to think electrons moved in orbits around the nucleus. How do scientists currently describe the movement of electrons?

111.
The lowest energy level of an atom is filled. Its second level contains three additional electrons. What type of atom is it? Explain your answer.

112.
Find the names of each of the following elements on the periodic table: Ag, As, Ca, Cl, I, Ir, Si, Ti. Classify each element as a metal, nonmetal, or metalloid.

113.
Except during World War II when steel pennies were made, pennies minted before 1984 were made entirely of copper. Pennies made later have a core of zinc covered by a thin layer of copper. Nickels contain about 25% copper and 75% nickel. Classify each type of coin in terms of elements, compounds, homogeneous mixtures, and heterogeneous mixtures.

114.
Use the example of inflating a flat tire after a repair to explain why air is matter.

115.
How are the airplane models that can be bought at a toy or hobby shop different from the models that scientists have made of atoms?

116.
Give four examples of properties of nonmetals that are exactly the opposite of properties of metals.

117.
Oxygen gas normally exists as O2 molecules. Each molecule contains two oxygen atoms. Is O2 a compound? Explain your answer.

118.
Lavoisier used the burning of wood to demonstrate conservation of mass. Explain why burning wood in a fireplace does not duplicate the experimental setup Lavoisier must have used.

119.
How did Thomson demonstrate the existence of the electron?

120.
What did Rutherford expect to happen when he bombarded metal foil with alpha particles? How did his results change the model of the atom?

121.
The operating system and programs that run on a computer depend on tiny electrical circuit boards called chips, which are made of materials called semi-conductors. Based on the label "semi-conductor," which type of element would you predict is used to make computer chips? Explain.

122.
Discuss the likelihood that the current model of the atom will be the final model of the atom.

123.
Suppose you found a sample of an element with the following properties: it is a dim yellow solid at room temperature, which shatters when hit with a hammer. How would you classify the element, and where would you expect to find it on the periodic table? Explain.

124.
Draw models of lithium-6 and lithium-7, two isotopes of lithium. Locate and label the subatomic particles in each model. How do the two models differ?

125.
Use the periodic table to complete the data in Table 3-1.

Properties of Selected Elements
Symbol
Name
Atomic number
Average Atomic Mass

Fluorine


O





15

S


32.066
Table 3-1


126.
Consider the following stages in preparing a homemade birthday cake: (A) Place ingredients such as flour, sugar, and eggs into a mixing bowl; (B) Stir the ingredients to form a batter; (C) Pour the batter into two baking pans; (D) Bake as directed and cool on a baking rack; (E) Spread a raspberry filling between the layers of cooled cake; (F) Coat the cake with a butter frosting. At which stages is it a heterogeneous mixture?

127. Study the following diagram. Then label the atom using the correct terms from the list.

electron
electron cloud
neutron
nucleus
proton



128. Classify the following as matter or not matter.

a. hydrogen
b. a wish
c. the Sun
d. any atom
e. heat
f. light

129. Fill in the missing numbers in the table.

Element
Number of protons
Number of neutrons
Number of electrons
Atomic number
Mass number
A
3
4
3

7
B
2

2
2
4
C
11
12

11

D

6
6

12
E

18


35


Study diagrams A, B, and C below. Then, identify the particles that make up each stream and explain your reasoning.

Each diagram shows the path followed by a stream of particles moving between two electrically charged plates. The particles may be electrons, which carry a negative charge, alpha particles which carry a positive charge, or neutrons, which carry no net charge.


130. Diagram A:

131. Diagram B:

132. Diagram C:

133. Compare and contrast the properties of a homogeneous mixture such as salt water and a heterogeneous mixture such as muddy water.

134. Compare and contrast the composition of a compound having the formula CO with one having the formula CO2.

135. Thomson’s model of the atom pictured electrons embedded in a ball of positive charge. Why did Rutherford’s gold-foil experiment lead to a change in this model?

136. Why is it impossible for the atomic number of an element to be greater than its mass number?

Problem

137. Copper has two isotopes that are fairly common in nature: copper-63 and copper-65. The average atomic mass for copper is 63.546 u. Which isotope of copper is more common? Explain.

138. The metal copper forms three different compounds with the nonmetal oxygen. Based on the following ratio of copper to oxygen, write formulas for the three compounds:
(a) 1 to 1; (b) 2 to 1; (c) 4 to 1.

139. The metal aluminum forms the following compounds with nonmetals: aluminum fluoride (AlF3), aluminum nitride (AlN4), aluminum carbide (Al4C3), and aluminum oxide (Al2O3). What is the ratio of nonmetal atoms to metal atoms in each compound?

Essay

140. Suppose a new element with atomic number 120 is discovered. If some isotopes of this element have 122 neutrons and some have 124 neutrons, what can you infer about the atomic mass of the element? Explain your answer.

141. Why can you write a formula for a compound but not for a mixture?
6th Grade - CHapter 16 ONLINE REVIEW
Answer Section

MODIFIED TRUE/FALSE

1. ANS: F, conserved

PTS: 1 DIF: Webb's I OBJ: 2/1 STA: SC.A.1.3.5

2. ANS: T PTS: 1 DIF: Webb's I
OBJ: 5/2 STA: SC.A.1.3.1

3. ANS: F, compounds

PTS: 1 DIF: Webb's I OBJ: 9/3 STA: SC.A.1.3.1 SC.A.1.3.5

4. ANS: F, electron

PTS: 1 DIF: Webb's I OBJ: 3/1 STA: SC.A.2.3.2 SC.H.1.3.6

5. ANS: T PTS: 1 DIF: Webb's I
OBJ: 4/1 STA: SC.A.2.3.2

6. ANS: T PTS: 1 DIF: Webb's I
OBJ: 6/2 STA: SC.A.2.3.2

7. ANS: F, electrons

PTS: 1 DIF: Webb's I OBJ: 3/1 STA: SC.A.2.3.2

8. ANS: T PTS: 1 DIF: Webb's I
OBJ: 1/1 STA: SC.A.1.3.2

9. ANS: F, has mass

PTS: 1

10. ANS: T PTS: 1

11. ANS: F, electron

PTS: 1

12. ANS: F, 24

PTS: 1

13. ANS: T PTS: 1

MULTIPLE CHOICE

14. ANS: B PTS: 1 DIF: Webb's II STA: SC.A.2.3.2

15. ANS: B PTS: 1 DIF: Webb's II STA: SC.A.2.3.2

16. ANS: C PTS: 1 DIF: Webb's I STA: SC.A.2.3.2

17. ANS: A PTS: 1 DIF: Webb's I STA: SC.A.1.3.1

18. ANS: B PTS: 1 DIF: Webb's I STA: SC.A.2.3.2

19. ANS: C PTS: 1 DIF: Webb's II STA: SC.A.2.3.2

20. ANS: A PTS: 1 DIF: Webb's I STA: SC.A.2.3.2

21. ANS: C PTS: 1 DIF: Webb's I STA: SC.A.2.3.2

22. ANS: D PTS: 1 DIF: Webb's I STA: SC.A.2.3.2

23. ANS: A PTS: 1 DIF: Webb's II STA: SC.A.2.3.2

24. ANS: D PTS: 1 DIF: Webb's II STA: SC.A.2.3.2 SC.H.1.3.1

25. ANS: B PTS: 1 DIF: Webb's I STA: SC.A.2.3.2

26. ANS: B PTS: 1 DIF: Webb's I STA: SC.A.2.3.2

27. ANS: A PTS: 1 DIF: Webb's I OBJ: 9/3

28. ANS: B PTS: 1 DIF: Webb's I OBJ: 10/3
STA: SC.A.1.3.1

29. ANS: C PTS: 1 DIF: Webb's I OBJ: 8/2
STA: SC.A.1.3.1

30. ANS: C PTS: 1 DIF: Webb's I OBJ: 9/3
STA: SC.A.1.3.1

31. ANS: D PTS: 1 DIF: Webb's I OBJ: 8/2
STA: SC.A.1.3.1

32. ANS: D PTS: 1 DIF: Webb's I OBJ: 8/2
STA: SC.A.1.3.1

33. ANS: D PTS: 1 DIF: Webb's I OBJ: 4/1
STA: SC.A.2.3.1

34. ANS: B PTS: 1 DIF: Webb's I OBJ: 9/3
STA: SC.A.1.3.1

35. ANS: A PTS: 1 DIF: Webb's II OBJ: 1/1

36. ANS: C PTS: 1 DIF: Webb's I OBJ: 5/2

37. ANS: A PTS: 1 DIF: Webb's I OBJ: 3/1
STA: SC.A.2.3.2

38. ANS: B PTS: 1 DIF: Webb's I OBJ: 10/3
STA: SC.A.1.3.5

39. ANS: D PTS: 1 DIF: Webb's I OBJ: 10/3
STA: SC.A.1.3.5

40. ANS: D PTS: 1 DIF: Webb's II OBJ: 6/2
STA: SC.A.2.3.2

41. ANS: B PTS: 1 DIF: Webb's II OBJ: 2/1

42. ANS: C PTS: 1 DIF: Webb's I OBJ: 1/1
STA: SC.A.1.3.1

43. ANS: D PTS: 1

44. ANS: B PTS: 1

45. ANS: C PTS: 1

46. ANS: C PTS: 1

47. ANS: D PTS: 1

48. ANS: B PTS: 1

49. ANS: A PTS: 1

50. ANS: A PTS: 1

51. ANS: D PTS: 1

52. ANS: A PTS: 1

53. ANS: B PTS: 1

54. ANS: D PTS: 1

55. ANS: C PTS: 1

56. ANS: D PTS: 1

COMPLETION

57. ANS: atoms

PTS: 1 DIF: Webb's I OBJ: 2/1 STA: SC.A.2.3.2

58. ANS: homogeneous

PTS: 1 DIF: Webb's II OBJ: 10/3 STA: SC.A.1.3.1

59. ANS: metals

PTS: 1 DIF: Webb's I OBJ: 5/2 STA: SC.A.1.3.1

60. ANS: heterogeneous

PTS: 1 DIF: Webb's I OBJ: 10/3 STA: SC.A.1.3.1

61. ANS: substance

PTS: 1 DIF: Webb's I OBJ: 9/3 STA: SC.A.1.3.1

62. ANS: metalloids

PTS: 1 DIF: Webb's I OBJ: 8/2 STA: SC.A.1.3.1

63. ANS: nucleus

PTS: 1 DIF: Webb's I OBJ: 4/1 STA: SC.A.2.3.2

64. ANS: isotopes

PTS: 1 DIF: Webb's I OBJ: 7/2 STA: SC.A.1.3.1

65. ANS: neutrons

PTS: 1 DIF: Webb's I OBJ: 7/2 STA: SC.A.1.3.1

66. ANS: atom

PTS: 1

67. ANS: elements

PTS: 1

68. ANS: atomic number

PTS: 1

69. ANS: metals

PTS: 1

70. ANS: between the metals and nonmetals

PTS: 1

71. ANS: nonmetals

PTS: 1

72. ANS: metalloids

PTS: 1

73. ANS: metals

PTS: 1

74. ANS: compound

PTS: 1

75. ANS: NH3

PTS: 1

76. ANS: air

PTS: 1

77. ANS: you can see its individual parts

PTS: 1

MATCHING

78. ANS: D PTS: 1 DIF: Webb's II OBJ: 5/2
STA: SC.A.1.3.1

79. ANS: B PTS: 1 DIF: Webb's II OBJ: 5/2
STA: SC.A.1.3.1

80. ANS: A PTS: 1 DIF: Webb's II OBJ: 9/3
STA: SC.A.1.3.1

81. ANS: E PTS: 1 DIF: Webb's II OBJ: 9/3
STA: SC.A.1.3.1

82. ANS: C PTS: 1 DIF: Webb's II OBJ: 5/2
STA: SC.A.1.3.1

83. ANS: D PTS: 1 DIF: Webb's II OBJ: 5/2
STA: SC.A.1.3.1

84. ANS: A PTS: 1 DIF: Webb's II OBJ: 5/2
STA: SC.A.1.3.1

85. ANS: C PTS: 1 DIF: Webb's II OBJ: 9/3
STA: SC.A.1.3.1

86. ANS: B PTS: 1 DIF: Webb's II OBJ: 9/3
STA: SC.A.1.3.1

87. ANS: B PTS: 1

88. ANS: R PTS: 1

89. ANS: H PTS: 1

90. ANS: E PTS: 1

91. ANS: P PTS: 1

92. ANS: Q PTS: 1

93. ANS: N PTS: 1

94. ANS: K PTS: 1

95. ANS: F PTS: 1

96. ANS: C PTS: 1

97. ANS: J PTS: 1

98. ANS: G PTS: 1

99. ANS: I PTS: 1

100. ANS: A PTS: 1

101. ANS: D PTS: 1

102. ANS: M PTS: 1

103. ANS: O PTS: 1

104. ANS: L PTS: 1

SHORT ANSWER

105. ANS:
Homogeneous and heterogeneous mixtures are present. The sand and water are one type of heterogeneous mixture. The toys and the sand are another. The lemonade is a homogeneous mixture because, unlike the sand and toys, the different parts of the mixture cannot be seen.

PTS: 1 DIF: Webb's II STA: SC.A.2.3.2

106. ANS:
Because Element A is shiny, it is either a metal or metalloid. It could be either because both conduct heat--although metalloids do not conduct heat as well as metals. Element B is most likely a nonmetal because it is not shiny.

PTS: 1 DIF: Webb's III STA: SC.A.2.3.2

107. ANS:
Add water to dissolve the sugar. Filter to separate the water from the sand. Evaporate the water to recover the sugar.

PTS: 1 DIF: Webb's III OBJ: 10/3 STA: SC.A.1.3.1

108. ANS:
The contents of gasoline can vary. It is a mixture, and its ingredients appear to be well mixed, so it is a homogeneous mixture.

PTS: 1 DIF: Webb's II OBJ: 10/3 STA: SC.A.1.3.1

109. ANS:
A compound because the ice contains the same amounts of elements as the liquid water even though it is in a different physical state.

PTS: 1 DIF: Webb's II OBJ: 9/3 STA: SC.A.1.3.1 SC.A.1.3.5

110. ANS:
Electrons move in an electron cloud.

PTS: 1 DIF: Webb's II OBJ: 4/1 STA: SC.A.2.3.2 SC.H.1.3.1

111. ANS:
Because it takes two electrons to fill the lowest energy level, the atom has a total of five electrons and, thus, a total of five protons; the element with atomic number five is boron.

PTS: 1 DIF: Webb's II OBJ: 6/2 STA: SC.A.2.3.2

112. ANS:
Ag: Silver, metal; As: arsenic, metalloid; Ca: calcium, metal; Cl: chlorine, nonmetal; I: iodine, nonmetal; Ir: iridium, metal; Si: silicon, metalloid; Ti: titanium, metal.

PTS: 1 DIF: Webb's II OBJ: 8/2 STA: SC.A.1.3.1

113. ANS:
All-copper pennies are examples of an element. Nickels are a homogeneous mixture of copper and nickel. Pennies in which zinc and copper are layered are a heterogeneous mixture.

PTS: 1 DIF: Webb's III OBJ: 10/3 STA: SC.A.1.3.1

114. ANS:
When someone forces air into the tire, the tire expands because the air takes up space, which is one property of matter.

PTS: 1 DIF: Webb's II OBJ: 1/1

115. ANS:
The plane models are physical, scale models based on large visible objects. The models of the atom are mental objects based on items that the scientists could not see directly. Drawings used to represent these mental models may not be drawn to scale.

PTS: 1 DIF: Webb's II OBJ: 4/1 STA: SC.A.2.3.2

116. ANS:
Unlike metals, nonmetals are poor conductors of heat, poor conductors of electricity, brittle instead of malleable when solid, and dull instead of shiny when solid.

PTS: 1 DIF: Webb's II OBJ: 8/2 STA: SC.A.1.3.1

117. ANS:
No, a compound must contain atoms from more than one element.

PTS: 1 DIF: Webb's II OBJ: 9/3 STA: SC.A.1.3.1

118. ANS:
In a fireplace, only the mass of the wood and of the ashes could be measured. Lavoisier would have used a closed system to measure the quantity of oxygen added and collect the gases produced.

PTS: 1 DIF: Webb's II OBJ: 2/1 STA: SC.A.1.3.5

119. ANS:
Thomson observed beams of particles being bent toward a positively charged plate.

PTS: 1 DIF: Webb's II OBJ: 3/1 STA: SC.A.2.3.1

120. ANS:
He expected the paths of the particles to be deflected by the charged particles in the foil. Because most of the alpha particles passed straight through with no deflection, Rutherford concluded that atoms are mainly empty space.

PTS: 1 DIF: Webb's II OBJ: 4/1 STA: SC.A.2.3.1 SC.H.1.3.1

121. ANS:
Metalloids because their ability to conduct electricity lies somewhere between the good metallic conductors and the poor nonmetallic conductors.

PTS: 1 DIF: Webb's II OBJ: 8/2 STA: SC.A.1.3.1

122. ANS:
Based on history, models evolve from new evidence. As scientists explore subatomic particles, the model is likely to be altered.

PTS: 1 DIF: Webb's II OBJ: 4/1 STA: SC.A.2.3.2 SC.H.1.3.1

123. ANS:
Although it is solid at room temperature, it is not a shiny, malleable metal. The element (sulfur) would be found among the nonmetals on the right side of the table.

PTS: 1 DIF: Webb's II OBJ: 8/2 STA: SC.A.1.3.1

124. ANS:
The lithium-6 model should show a nucleus with three protons and three neutrons. The lithium-7 model should show a nucleus with three protons and four neutrons. Each model should have three electrons; two should be closer to the nucleus than the third.

PTS: 1 DIF: Webb's III OBJ: 7/2 STA: SC.A.1.3.1 SC.A.2.3.2

125. ANS:

Properties of Selected Elements
Symbol
Name
Atomic number
Average Atomic Mass
F
Fluorine
9
18.998
O
Oxygen
8
15.999
P
Phosophorous
15
30.974
S
Sulfur
16
32.066


PTS: 1 DIF: Webb's III OBJ: 5/2 STA: SC.A.1.3.1

126. ANS:
At stages B, C, and D it is homogeneous; at stages A, E, and F, it is heterogeneous. Students may note that two additional homogeneous mixtures are introduced as stages E and F to produce the final heterogeneous result.

PTS: 1 DIF: Webb's II OBJ: 10/3 STA: SC.A.1.3.1

127. ANS:

PTS: 1

128. ANS:
a. matter
b. not matter
c. matter
d. matter
e. not matter
f. not matter

PTS: 1

129. ANS:

Element
Number of protons
Number of neutrons
Number of electrons
Atomic number
Mass number
A
3
4
3
3
7
B
2
2
2
2
4
C
11
12
11
11
23
D
6
6
6
6
12
E
17
18
17
17
35


PTS: 1

130. ANS:
Students should identify the particles as electrons; reasoning should indicate that negatively charged particles would be attracted toward the positive (+) plate and away from the negative (–) plate.

PTS: 1

131. ANS:
Students should identify the particles as neutrons; reasoning should indicate that uncharged particles would not be affected by the charges on the plates.

PTS: 1

132. ANS:
Students should identify the particles as alpha particles; reasoning should indicate that positive (+) particles would be attracted toward the negative (–) plate and away from the positive (+) plate.

PTS: 1

133. ANS:
Both mixtures will be made up of more than one substance. In a homogenous mixture, the substances will be evenly distributed throughout. In a heterogeneous mixture, the distribution of substances will be uneven.

PTS: 1

134. ANS:
Both compounds will be made up of the same elements–carbon and oxygen. One will be made up of two atoms, one carbon and one oxygen. The other will be made up of three atoms, one carbon and two oxygen.

PTS: 1

135. ANS:
Rutherford’s experiment showed that much of the atom is empty space, with most of the mass concentrated in a dense central nucleus.

PTS: 1

136. ANS:
Atomic number is the number of protons; mass number is the sum of protons and neutrons. Therefore, atomic number is always less than mass number if there is even one neutron in the nucleus.

PTS: 1

PROBLEM

137. ANS:
The average atomic mass is much closer to 63 than 65, so copper-63 is the more common isotope.

PTS: 1 DIF: Webb's II OBJ: 7/2 STA: SC.A.1.3.1

138. ANS:
(a) CuO, copper(II) oxide; (b) C2O copper(I) oxide; (c) C4O, copper suboxide

PTS: 1 DIF: Webb's II OBJ: 9/3 STA: SC.A.1.3.1

139. ANS:
In AlF3, 3 to 1; in AlN4, 4 to 1; in Al4C3, 3 to 4; in Al2O3, 3 to 2

PTS: 1 DIF: Webb's II OBJ: 9/3 STA: SC.A.1.3.1

ESSAY

140. ANS:
The atomic mass will be greater than 240, since all of the isotopes will have 120 protons and 120 or more neutrons.

PTS: 1

141. ANS:
Any given compound is always made of the same elements in the same proportion by mass. So you can write a formula to represent those elements. The proportions of a mixture vary from one mixture to another or from one part of a mixture to another.

PTS: 1