Question 1

Which of the following best describes a compound?
Correct answer: A substance composed of two or more elements chemically bonded together.

Accepted Answer

A substance composed of two or more elements chemically bonded together.

Question 2

A student mixes sand and iron filings together. Which statement best describes the result?
Correct answer: A mixture is formed, which can be separated by physical means.

Accepted Answer

A mixture is formed, which can be separated by physical means.

Question 3

Which of the following is an example of a physical change?
Correct answer: Dissolving sugar in water.

Accepted Answer

Dissolving sugar in water.

Question 4

Which property is intensive and does NOT depend on the amount of substance present?
Correct answer: Density

Accepted Answer

Density

Question 5

A sample of water is heated from 20°C to 100°C and then boiled. Which of the following best describes the changes that occur?
Correct answer: Only physical changes occur because the composition of water remains the same.

Accepted Answer

Only physical changes occur because the composition of water remains the same.

Question 6

Which scenario best illustrates a chemical change?
Correct answer: A silver spoon tarnishing after exposure to air.

Accepted Answer

A silver spoon tarnishing after exposure to air.

Question 7

Which of the following statements about atoms is correct?
Correct answer: Atoms are the fundamental units of matter.

Accepted Answer

Atoms are the fundamental units of matter.

Question 8

A chemist separates a mixture of ethanol and water by distillation. What type of change is this and why?
Correct answer: Physical change, because the substances retain their original identities.

Accepted Answer

Physical change, because the substances retain their original identities.

Question 9

Which of the following is NOT a pure substance?
Correct answer: Air

Accepted Answer

Air

Question 10

A student claims that mass is an intensive property. Which argument best refutes this claim?
Correct answer: Mass depends on the amount of substance present, so it is an extensive property.

Accepted Answer

Mass depends on the amount of substance present, so it is an extensive property.

Question 11

Which of the following best explains why salt water is considered a mixture?
Correct answer: The components can be separated by physical means and retain their individual properties.

Accepted Answer

The components can be separated by physical means and retain their individual properties.

Question 12

Which of the following is an example of a pure substance?
Correct answer: Carbon dioxide gas

Accepted Answer

Carbon dioxide gas

Question 13

A patient is given a saline solution intravenously. Which statement about the solution is correct?
Correct answer: It is a mixture because it contains salt and water physically combined.

Accepted Answer

It is a mixture because it contains salt and water physically combined.

Question 14

Which of the following best distinguishes a chemical change from a physical change?
Correct answer: A chemical change results in the formation of new substances, while a physical change does not.

Accepted Answer

A chemical change results in the formation of new substances, while a physical change does not.

Question 15

Which of the following is an example of an extensive property?
Correct answer: Volume

Accepted Answer

Volume

Question 16

A gold ring is melted and reshaped into a new design. Which statement is true about this process?
Correct answer: It is a physical change because the composition of gold remains unchanged.

Accepted Answer

It is a physical change because the composition of gold remains unchanged.

Question 17

Which of the following best describes the difference between an element and a compound?
Correct answer: An element contains only one type of atom, while a compound contains two or more different elements chemically bonded.

Accepted Answer

An element contains only one type of atom, while a compound contains two or more different elements chemically bonded.

Question 18

A student observes that the density of a liquid remains the same regardless of the amount measured. What type of property is density?
Correct answer: Intensive property

Accepted Answer

Intensive property

Question 19

Which of the following best illustrates the concept of matter?
Correct answer: A helium balloon, because it has mass and occupies space.

Accepted Answer

A helium balloon, because it has mass and occupies space.

Question 20

During a laboratory experiment, a student combines two colorless solutions and observes the formation of a yellow solid. What type of change has occurred?
Correct answer: A chemical change, because a new substance (the yellow solid) has formed.

Accepted Answer

A chemical change, because a new substance (the yellow solid) has formed.

Classification of Matter: Key Concepts

Study Guide - Practice Questions

Study Guide - Flashcards