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