Reading 5 "Physical and Chemical Properties and Changes"
→ Sugar, water, and aluminum are different substances. Each substance has specific properties that do not depend on the quantity of the substance. Properties that can be used to identify or characterize a substance—and distinguish that substance from other substances--are called characteristic properties. They are subdivided into two categories: physical properties and chemical properties.
The characteristic physical properties of a substance are those that identify the substance without causing a change in the composition of the substance. They do not depend on the quantity of substance.
Color, odor, density, melting point, boiling point, hardness, metallic luster or shininess, ductility, malleability, and viscosity are all characteristic physical properties. For exam pie, aluminum is a metal that is both ductile and malleable. 
Another example of a physical property is water. Whether a small pan of water is raised to its boiling point or a very large kettle of water is raised to its boiling point, the tem- perature at which the water boils is the same value, 100 degrees C or 212 degrees F. 
Similarly, the freezing point of water is 0 degrees C or 32 degrees F. These values are independent of quantity. 
→ Sugar, water, and aluminum are different substances. Each substance has specific properties that do not depend on the quantity of the substance. Properties that can be used to identify or characterize a substance—and distinguish that substance from other substances--are called characteristic properties. They are subdivided into two categories: physical properties and chemical properties.
The characteristic physical properties of a substance are those that identify the substance without causing a change in the composition of the substance. They do not depend on the quantity of substance.
Color, odor, density, melting point, boiling point, hardness, metallic luster or shininess, ductility, malleability, and viscosity are all characteristic physical properties. For exam pie, aluminum is a metal that is both ductile and malleable. Another example of a physical property is water. Whether a small pan of water is raised to its boiling point or a very large kettle of water is raised to its boiling point, the tem- perature at which the water boils is the same value, 100 degrees C or 212 degrees F. Similarly, the freezing point of water is 0 degrees C or 32 degrees F. These values are independent of quantity.
单选题
According to paragraph 1, what do physical properties and chemical properties have in common?
A. They are both used to create most of the substances.
B. They include basic substances like sugar and water.
C. They are classified as characteristic properties of substances.
D. They change in proportion to the amount of the substance.
A. They are both used to create most of the substances.
B. They include basic substances like sugar and water.
C. They are classified as characteristic properties of substances.
D. They change in proportion to the amount of the substance.
【正确答案】
C
【答案解析】"They [characteristic properties] are subdivided into two categories: physical properties and chemical properties." Choice A is not correct because they are used to identify or characterize a substance, not to create a substance. Choice B is not correct because sugar and water are substances, but the physical and chemical properties of them are not identified in the paragraph. Choice D is not correct because the properties do not depend on the quantity of the substance.
单选题
The word pertain in the passage is closest in meaning to
A. compare
B. relate
C. explain
D. change
A. compare
B. relate
C. explain
D. change
【正确答案】
B
【答案解析】In this passage, relate is a synonym for "pertain." Context comes from the word "relate" in the previous sentence.
单选题
The word which in the passage refers to
A. properties
B. tendency
C. density
D. ratio
A. properties
B. tendency
C. density
D. ratio
【正确答案】
C
【答案解析】... some intensive physical properties include the tendency to dissolve in water, electrical conductivity, and density, which [density] is the ratio of mass to volume." The pronoun "which" does not refer to Choices A, B, or D.
单选题
According to the passage, a carcinogen
A. explodes under pressure
B. conducts electricity
C. causes cancer
D. tarnishes in air
A. explodes under pressure
B. conducts electricity
C. causes cancer
D. tarnishes in air
【正确答案】
C
【答案解析】... to act as a poison or carcinogen (cancer-causing agent)." An explanation of a word or phrase often appears immediately after it in parentheses. Choices A, B, and D are not correct because they are intensive chemical properties that are mentioned before the reference to a carcinogen.
单选题
Which of the sentences below best expresses the information in the highlighted statement in the passage? The other choices change the meaning or leave out important information.
A. Properties that are classified as intensive identify the type of substance and the extent of it present in the surrounding matter.
B. The quantity of a substance influences its extensive properties, but the characteristics of the substance define the intensive properties.
C. Where the intensive and extensive properties are found in substances is important in identifying their characteristics.
D. Both intensive and extensive properties tend to have quantitative rather than qualitative characteristics present.
A. Properties that are classified as intensive identify the type of substance and the extent of it present in the surrounding matter.
B. The quantity of a substance influences its extensive properties, but the characteristics of the substance define the intensive properties.
C. Where the intensive and extensive properties are found in substances is important in identifying their characteristics.
D. Both intensive and extensive properties tend to have quantitative rather than qualitative characteristics present.
【正确答案】
B
【答案解析】The quantity of a substance paraphrases "the amount present" in reference to extensive properties and the characteristics of the substance paraphrases "characterize a particular kind of matter" in reference to intensive properties.
单选题
In paragraph 8, the author contrasts the concepts of physical and chemical changes by
A. listing several types for each concept
B. providing clear definitions for them
C. identifying the common characteristics
D. using a wax candle as an example
A. listing several types for each concept
B. providing clear definitions for them
C. identifying the common characteristics
D. using a wax candle as an example
【正确答案】
D
【答案解析】"When a candle is burned, there are both physical and chemical changes." Choice A is not correct because only the example of the candle is mentioned. Choice B is not correct because the meaning is explained by example, not by definition. Choice C is not correct because the common characteristics were mentioned in previous paragraphs.
单选题
The word unique in the passage is closest in meaning to
A. distinctive
B. idealized
C. primary
D. significant
A. distinctive
B. idealized
C. primary
D. significant
【正确答案】
A
【答案解析】In this passage, distinctive is a synonym for "unique./
单选题
What can be inferred about phase changes?
A. They are always chemical changes.
B. They are sometimes physical changes.
C. They are dependent on extensive properties.
D. They usually produce new substances.
A. They are always chemical changes.
B. They are sometimes physical changes.
C. They are dependent on extensive properties.
D. They usually produce new substances.
【正确答案】
B
【答案解析】"This is a phase change (liquid to gas) which is a physical change." Because this example of a physical change is provided, it must be concluded that phase changes are sometimes physical changes. Choice A is not correct because the example is a physical change, not a chemical change. Choice C is not correct because the quantity of a substance (extensive properties) is not mentioned in the discussion on phase changes. Choice D is not correct because in a physical change the fundamental composition of a substance has not changed.
单选题
The word critical in the passage is closest in meaning to
A. last
B. important
C. difficult
D. simple
A. last
B. important
C. difficult
D. simple
【正确答案】
B
【答案解析】In this passage, important is a synonym for"critical./
单选题
According to the passage, the classification of characteristic properties as "physical" or "chemical" is determined by
A. whether there has been a change in the structure of the substance
B. what happens when the quantity of the substance is increased
C. their classification as either extensive or intensive samples
D. the disappearance of a substance from one form to another
A. whether there has been a change in the structure of the substance
B. what happens when the quantity of the substance is increased
C. their classification as either extensive or intensive samples
D. the disappearance of a substance from one form to another
【正确答案】
A
【答案解析】"Has the fundamental composition of the substance changed? In a chemical change...it has, but in a physical change, it has not." Choice B is not correct because the quantity refers to extensive properties, not to the difference between physical or chemical properties. Choice C is not correct because both physical and chemical properties are intensive properties. Choice D is not correct because the apparent disappearance of a substance is not necessarily a sign that we are observing a chemical change.
单选题
All of the following are mentioned as characteristic physical properties EXCEPT
A. dissolving in water
B. carrying an electrical charge
C. resisting continuous flow
D. decomposing when heated
A. dissolving in water
B. carrying an electrical charge
C. resisting continuous flow
D. decomposing when heated
【正确答案】
D
【答案解析】"The following questions pertain to the chemical properties of a substance: '... Does it decompose...when heated?'" Choices A and B are mentioned as characteristic physical properties in paragraph 4. Choice C is mentioned as a characteristic physical property in paragraph 2 in the discussion of "viscosity./
单选题
Look at the four squares [■] that show where the following sentence could be inserted in the passage.
It can be made into wire or thin, flexible sheets.
Where could the sentence best be added?
Click on a square [■] to insert the sentence in the passage.
A. Square Ａ.
B. Square Ｂ.
C. Square Ｃ.
D. Square Ｄ.
It can be made into wire or thin, flexible sheets.
Where could the sentence best be added?
Click on a square [■] to insert the sentence in the passage.
A. Square Ａ.
B. Square Ｂ.
C. Square Ｃ.
D. Square Ｄ.
【正确答案】
B
【答案解析】Pronoun reference is a transitional device that connects the insert sentence with the previous sentence. The pronoun "It" in the insert sentence refers to "aluminum" in the previous sentence. The description of aluminum as "ductile" and "malleable" in the previous sentence means that this metal can be made into wire or shaped into flexible sheets as stated in the insert sentence.
填空题
Directions: Complete the table by matching the phrases on the left with the headings on the right. Select the appropriate answer choices and drag them to the characteristic properties to which they refer. TWO of the answer choices will NOT be used. This question is worth 4 points.
To delete an answer choice, click on it. To see the passage, click on View Text.
Properties
A. Color of the substance
B. Reaction in an acid
C. Decomposition in heat
D. Temperature at which it boils
E. The tendency to shine
F. The inclination to tarnish
G. The shape of the substance
(H) Toxic if swallowed or inhaled
(I) The relative amount in nature
Physical Properties
·__________
·__________
·__________
Chemical Properties
·__________
·__________
·__________
To delete an answer choice, click on it. To see the passage, click on View Text.
Properties
A. Color of the substance
B. Reaction in an acid
C. Decomposition in heat
D. Temperature at which it boils
E. The tendency to shine
F. The inclination to tarnish
G. The shape of the substance
(H) Toxic if swallowed or inhaled
(I) The relative amount in nature
Physical Properties
·__________
·__________
·__________
Chemical Properties
·__________
·__________
·__________