Law of conservation of mass: $$\text{In a chemical reaction, matter is neither created nor destroyed.}$$

Question 1

Which of the following best describes the central goal of chemistry?

Accepted Answer

To understand the behavior of matter by studying the behavior of atoms and molecules.

Question 2

Graphite and diamond are both made of carbon, yet they have very different properties. What is the primary reason for this difference?

Accepted Answer

The arrangement of carbon atoms in each substance.

Question 3

Which of the following statements about the scientific method is correct?

Accepted Answer

It involves observation, hypothesis formulation, experimentation, and the development of laws and theories.

Question 4

Antoine Lavoisier's experiments on combustion led to which important scientific law?

Accepted Answer

Law of conservation of mass: $$	ext{In a chemical reaction, matter is neither created nor destroyed.}$$

Question 5

A student observes that a metal gains mass when it is heated in air. Which step of the scientific method should the student perform next?

Accepted Answer

Formulate a hypothesis to explain the observation.

Question 6

Which of the following is a key difference between a scientific law and a scientific theory?

Accepted Answer

A law summarizes a series of related observations; a theory gives the underlying reasons for them.

Question 7

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

Accepted Answer

Sweetened tea

Question 8

Which of the following statements about solids is correct?

Accepted Answer

Atoms or molecules in a solid are packed closely together in fixed locations and vibrate but do not move past each other.

Question 9

Glass and plastic are examples of which type of solid?

Accepted Answer

Amorphous solids

Question 10

Which property makes gases compressible compared to solids and liquids?

Accepted Answer

Atoms or molecules in gases have a lot of space between them.

Question 11

A sample of matter is composed of two or more substances that can be seen and separated by physical means. Which type of matter is this?

Accepted Answer

Heterogeneous mixture

Question 12

Which of the following is a pure substance that cannot be chemically broken down into simpler substances?

Accepted Answer

Element

Question 13

Which of the following best describes a compound?

Accepted Answer

A substance composed of two or more elements in fixed, definite proportions.

Question 14

Which of the following is an example of a crystalline solid?

Accepted Answer

Table salt

Question 15

Which of the following statements about liquids is correct?

Accepted Answer

Liquids have a fixed volume but not a fixed shape.

Question 16

A scientist proposes that all metals will react with oxygen to form a white powder. What makes this statement a poor hypothesis?

Accepted Answer

It is not falsifiable, as it cannot be tested for all metals.

Question 17

Which of the following best illustrates the empirical approach in chemistry?

Accepted Answer

Basing conclusions on observation and experiment.

Question 18

Which of the following is true about scientific theories?

Accepted Answer

They provide models that explain why nature behaves as it does.

Question 19

Which of the following is NOT a characteristic of matter?

Accepted Answer

It has no mass and does not occupy space.

Question 20

A sample of sweetened tea is best classified as which of the following?

Accepted Answer

Homogeneous mixture

Foundations of Chemistry: Matter, Scientific Method, and Classification

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