Question 1

Which of the following best describes the Law of Constant Composition (Law of Definite Proportions)?

Accepted Answer

A compound always contains the same elements in the same proportion by mass, regardless of the sample size.

Question 2

A sample of matter is uniform throughout and can be separated into two substances by physical means. How should this sample be classified?

Accepted Answer

Homogeneous mixture (solution)

Question 3

Which of the following is NOT a compound?

Accepted Answer

Oxygen gas, $\mathrm{O_2}$

Question 4

Which of the following statements about elements and compounds is correct?

Accepted Answer

Elements are pure substances that cannot be broken down by chemical means.

Question 5

A beaker contains a blue solution and a blue solid. Which classification best describes this system?

Accepted Answer

Heterogeneous mixture

Question 6

Which of the following is a correct representation of a molecule of ethylene glycol?

Accepted Answer

A group of atoms containing carbon, hydrogen, and oxygen in a fixed ratio

Question 7

Which of the following is a physical property?

Accepted Answer

The boiling point of water

Question 8

Which element makes up the largest percentage by mass of the Earth's crust?

Accepted Answer

Oxygen

Question 9

A sample contains only molecules made of two different types of atoms chemically bonded together. Which classification best describes this sample?

Accepted Answer

Compound

Question 10

Which of the following is an example of a homogeneous mixture?

Accepted Answer

Salt dissolved in water

Question 11

Which of the following best explains why water is considered a compound?

Accepted Answer

It can be separated into hydrogen and oxygen by chemical means.

Question 12

Which of the following is a chemical property?

Accepted Answer

Reactivity of sodium with water

Question 13

Which of the following is true about mixtures?

Accepted Answer

They can be separated into their components by physical means.

Question 14

Which of the following is a correct symbol for an element, based on the periodic table?

Accepted Answer

Fe for iron

Question 15

A student observes that a sample of matter can be separated into simpler substances only by chemical means. Which classification best fits this sample?

Accepted Answer

Compound

Question 16

Which of the following best describes the difference between a compound and a mixture?

Accepted Answer

A compound has a fixed composition, while a mixture can have variable composition.

Question 17

Which of the following is NOT a property of a substance?

Accepted Answer

Composition varies from sample to sample

Question 18

Which of the following is a correct statement about atoms and molecules?

Accepted Answer

Molecules are groups of atoms bonded together and can be elements or compounds.

Question 19

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

Accepted Answer

Electrolysis of water to produce hydrogen and oxygen gases

Question 20

Which of the following elements is present in the highest percentage by mass in the human body?

Accepted Answer

Oxygen

Chapter 1: Introduction to Matter, Energy, and Measurement

Study Guide - Practice Questions

Study Guide - Flashcards