CHEM 121 - Module 1 Exam: Matter, Measurement, and Dimensional
Analysis 2026/2027 UPDATE
1. Which of the following is the best definition of matter?
A. Anything that has mass and occupies space.
B. Anything that has weight and occupies space.
C. Energy that is transformed into physical objects.
D. The study of atoms and molecules only.
Answer: A
Rationale: Matter is defined as anything that has mass and takes up space (volume).
2. Which state of matter has a definite volume but takes the shape of its
container?
A. Solid
B. Liquid
C. Gas
D. Plasma
Answer: B
Rationale: Liquids have a definite volume but no definite shape; solids have both, and
gases have neither.
,3. A substance that cannot be broken down into simpler substances by chemical
means is called a(n):
A. Element
B. Compound
C. Homogeneous mixture
D. Heterogeneous mixture
Answer: A
Rationale: Elements are the simplest form of matter that retains its chemical properties
and cannot be decomposed further.
4. Which of the following is an example of a homogeneous mixture?
A. Oil and water
B. Saltwater
C. Granite rock
D. Italian salad dressing
Answer: B
Rationale: Saltwater is a solution where the components are uniformly distributed,
making it a homogeneous mixture.
5. Which of the following describes a chemical property of iron?
A. It is a solid at room temperature.
B. It has a density of 7.87 g/cm³.
C. It reacts with oxygen to form rust.
D. It melts at 1538 degrees Celsius.
Answer: C
Rationale: Chemical properties describe the ability of a substance to undergo a specific
chemical change/reaction.
, 6. The process of a solid turning directly into a gas is called:
A. Sublimation
B. Deposition
C. Evaporation
D. Condensation
Answer: A
Rationale: Sublimation is the phase transition from solid to gas without passing through
the liquid phase.
7. How many significant figures are in the measurement 0.005080 meters?
A. 3
B. 6
C. 5
D. 4
Answer: D
Rationale: Leading zeros are not significant. Captive zeros and trailing zeros after a
decimal are significant. (5, 0, 8, 0).
8. Round the number 125.67 to three significant figures.
A. 125
B. 125.7
C. 126
D. 130
Answer: C
Rationale: The first three digits are 1, 2, and 5. Since the next digit is 6, we round up the 5
to 6.
Analysis 2026/2027 UPDATE
1. Which of the following is the best definition of matter?
A. Anything that has mass and occupies space.
B. Anything that has weight and occupies space.
C. Energy that is transformed into physical objects.
D. The study of atoms and molecules only.
Answer: A
Rationale: Matter is defined as anything that has mass and takes up space (volume).
2. Which state of matter has a definite volume but takes the shape of its
container?
A. Solid
B. Liquid
C. Gas
D. Plasma
Answer: B
Rationale: Liquids have a definite volume but no definite shape; solids have both, and
gases have neither.
,3. A substance that cannot be broken down into simpler substances by chemical
means is called a(n):
A. Element
B. Compound
C. Homogeneous mixture
D. Heterogeneous mixture
Answer: A
Rationale: Elements are the simplest form of matter that retains its chemical properties
and cannot be decomposed further.
4. Which of the following is an example of a homogeneous mixture?
A. Oil and water
B. Saltwater
C. Granite rock
D. Italian salad dressing
Answer: B
Rationale: Saltwater is a solution where the components are uniformly distributed,
making it a homogeneous mixture.
5. Which of the following describes a chemical property of iron?
A. It is a solid at room temperature.
B. It has a density of 7.87 g/cm³.
C. It reacts with oxygen to form rust.
D. It melts at 1538 degrees Celsius.
Answer: C
Rationale: Chemical properties describe the ability of a substance to undergo a specific
chemical change/reaction.
, 6. The process of a solid turning directly into a gas is called:
A. Sublimation
B. Deposition
C. Evaporation
D. Condensation
Answer: A
Rationale: Sublimation is the phase transition from solid to gas without passing through
the liquid phase.
7. How many significant figures are in the measurement 0.005080 meters?
A. 3
B. 6
C. 5
D. 4
Answer: D
Rationale: Leading zeros are not significant. Captive zeros and trailing zeros after a
decimal are significant. (5, 0, 8, 0).
8. Round the number 125.67 to three significant figures.
A. 125
B. 125.7
C. 126
D. 130
Answer: C
Rationale: The first three digits are 1, 2, and 5. Since the next digit is 6, we round up the 5
to 6.
