Question 1

Which of the following best describes an atom according to the study materials?

Accepted Answer

An atom is the basic unit of matter.

Question 2

Which property is considered intensive and does NOT depend on the amount of substance present?

Accepted Answer

Density

Question 3

A student mixes salt and water in a beaker. According to the notes, this mixture can be separated by which method?

Accepted Answer

Physical separation

Question 4

Which of the following is an example of a chemical change?

Accepted Answer

Burning wood

Question 5

Which statement correctly distinguishes between elements and compounds?

Accepted Answer

Elements are made of one kind of atom, while compounds are made of two or more different elements bonded together.

Question 6

Which of the following is a pure substance?

Accepted Answer

Oxygen gas ($$\mathrm{O_2$})$$

Question 7

A block of ice melts into water. What type of change is this, and why?

Accepted Answer

Physical change, because the composition does not change.

Question 8

Which of the following statements about mixtures is correct?

Accepted Answer

Mixtures can be separated by physical means.

Question 9

Which property would you use to distinguish between gold and iron, regardless of the amount present?

Accepted Answer

Density

Question 10

A student observes that burning wood produces ash and smoke. What type of change is this and what is the evidence?

Accepted Answer

Chemical change; new substances are formed.

Question 11

Which of the following is NOT a pure substance?

Accepted Answer

Air

Question 12

Which of the following best describes the study of chemistry?

Accepted Answer

The study of matter and how it changes.

Question 13

Which of the following is an example of an extensive property?

Accepted Answer

Mass

Question 14

A mixture of sand and iron filings can be separated by using a magnet. What does this demonstrate about mixtures?

Accepted Answer

Mixtures can be separated by physical means.

Question 15

Which of the following changes does NOT alter the chemical composition of a substance?

Accepted Answer

Melting ice

Question 16

Which statement is true about compounds?

Accepted Answer

Compounds are made of two or more different elements bonded together.

Question 17

Which of the following is an example of a physical property?

Accepted Answer

Density

Question 18

If a substance has a fixed composition and cannot be separated by physical means, it is most likely:

Accepted Answer

A pure substance

Question 19

Which of the following is a chemical property?

Accepted Answer

Ability to burn

Question 20

Which of the following best explains why density is an intensive property?

Accepted Answer

Density does not depend on the amount of substance present.

Introduction to General Chemistry: Fundamental Concepts

Study Guide - Practice Questions