Question 1

Which of the following best describes a scientific law?

Accepted Answer

A brief statement summarizing past observations and predicting future ones.

Question 2

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

Accepted Answer

Sand mixed with iron filings.

Question 3

A student observes water boiling and sees steam rising. At which level of matter is this observation made?

Accepted Answer

Macroscopic level

Question 4

Which of the following changes is a chemical change?

Accepted Answer

Burning a piece of paper.

Question 5

Which of the following statements about gases is correct?

Accepted Answer

Gases are compressible and take the shape and volume of their container.

Question 6

Which of the following is a physical property?

Accepted Answer

Density

Question 7

A sample of sodium chloride (NaCl) is dissolved in water. Which method would best separate the salt from the water?

Accepted Answer

Distillation

Question 8

Which of the following best describes a compound?

Accepted Answer

A substance composed of two or more elements chemically combined in fixed proportions.

Question 9

Which of the following is an example of potential energy?

Accepted Answer

A ball held at the top of a hill.

Question 10

Which of the following is the correct SI unit for mass?

Accepted Answer

$$\mathrm{kg}$$

Question 11

A hypothesis must be which of the following?

Accepted Answer

Falsifiable

Question 12

Which of the following best describes the atomic theory?

Accepted Answer

All matter is composed of tiny particles called atoms and molecules.

Question 13

Which of the following is a homogeneous mixture?

Accepted Answer

Sweetened tea

Question 14

Which of the following is NOT a physical property?

Accepted Answer

Ability to react with oxygen

Question 15

A student wants to separate a mixture of sand and salt. Which method should they use first?

Accepted Answer

Filtration

Question 16

Which of the following best describes a chemical property?

Accepted Answer

Ability to react with acid

Question 17

Which of the following is a correct statement about energy?

Accepted Answer

Total energy is the sum of kinetic energy and potential energy.

Question 18

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

Accepted Answer

Ice melting to form water.

Question 19

A student measures the height of a mountain as 4,025 feet. What is this height in meters? (1 meter = 3.28084 feet)

Accepted Answer

$$1,227\ \mathrm{m}$$

Question 20

Which of the following best describes a pure substance?

Accepted Answer

A substance with a constant composition that can be either an element or a compound.

General Chemistry I: Matter, Measurement, and Problem Solving

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