,CHEM 120 Exam 1 General Chemistry I Questions And Answers
2026/2027 Chamberlain
1.** A nurse is reviewing the scientific method. Which of the following is a
testable explanation for a phenomenon?
A) Theory
B) Hypothesis
C) Law
D) Observation
**Correct Answer:** B) Hypothesis
**Rationale:** A hypothesis is a testable, educated guess or explanation for a
phenomenon. It is the basis for experimentation. A theory (A) is a well-
substantiated explanation supported by evidence. A law (C) describes a
consistent relationship in nature. An observation (D) is a factual statement.
**2.** In a scientific experiment, the variable that is manipulated or changed
by the researcher is the:
A) Dependent variable
B) Control variable
C) Independent variable
D) Confounding variable
**Correct Answer:** C) Independent variable
,**Rationale:** The independent variable is what the researcher controls or
changes. The dependent variable (A) is the outcome that is measured. A
control variable (B) is kept constant to ensure a fair test.
**3.** What is the purpose of a control group in an experiment?
A) To provide a baseline for comparison
B) To test the hypothesis
C) To manipulate the independent variable
D) To measure the dependent variable
**Correct Answer:** A) To provide a baseline for comparison
**Rationale:** A control group is the standard against which the
experimental group is compared. It ensures that any observed effects are
due to the independent variable and not other factors. A negative control (A)
produces no result, while a positive control (B) produces a known result.
**4.** Which of the following is NOT considered matter?
A) Light
B) Air
C) Water
D) A rock
**Correct Answer:** A) Light
**Rationale:** Matter is anything that has mass and occupies space. Light is
energy, not matter. Air (B), water (C), and a rock (D) are all forms of matter.
, **5.** Which state of matter has a definite volume but takes the shape of its
container?
A) Solid
B) Liquid
C) Gas
D) Plasma
**Correct Answer:** B) Liquid
**Rationale:** Liquids have a definite volume but no definite shape,
conforming to the shape of their container. Solids (A) have a definite shape
and volume. Gases (C) have neither a definite shape nor volume.
**6.** Which of the following is a physical property?
A) Flammability
B) Reactivity with acid
C) Boiling point
D) Ability to rust
**Correct Answer:** C) Boiling point
**Rationale:** A physical property can be observed without changing the
substance's chemical identity. Boiling point, melting point, density, and color
are physical properties. Flammability (A), reactivity (B), and rusting (D) are
chemical properties.
2026/2027 Chamberlain
1.** A nurse is reviewing the scientific method. Which of the following is a
testable explanation for a phenomenon?
A) Theory
B) Hypothesis
C) Law
D) Observation
**Correct Answer:** B) Hypothesis
**Rationale:** A hypothesis is a testable, educated guess or explanation for a
phenomenon. It is the basis for experimentation. A theory (A) is a well-
substantiated explanation supported by evidence. A law (C) describes a
consistent relationship in nature. An observation (D) is a factual statement.
**2.** In a scientific experiment, the variable that is manipulated or changed
by the researcher is the:
A) Dependent variable
B) Control variable
C) Independent variable
D) Confounding variable
**Correct Answer:** C) Independent variable
,**Rationale:** The independent variable is what the researcher controls or
changes. The dependent variable (A) is the outcome that is measured. A
control variable (B) is kept constant to ensure a fair test.
**3.** What is the purpose of a control group in an experiment?
A) To provide a baseline for comparison
B) To test the hypothesis
C) To manipulate the independent variable
D) To measure the dependent variable
**Correct Answer:** A) To provide a baseline for comparison
**Rationale:** A control group is the standard against which the
experimental group is compared. It ensures that any observed effects are
due to the independent variable and not other factors. A negative control (A)
produces no result, while a positive control (B) produces a known result.
**4.** Which of the following is NOT considered matter?
A) Light
B) Air
C) Water
D) A rock
**Correct Answer:** A) Light
**Rationale:** Matter is anything that has mass and occupies space. Light is
energy, not matter. Air (B), water (C), and a rock (D) are all forms of matter.
, **5.** Which state of matter has a definite volume but takes the shape of its
container?
A) Solid
B) Liquid
C) Gas
D) Plasma
**Correct Answer:** B) Liquid
**Rationale:** Liquids have a definite volume but no definite shape,
conforming to the shape of their container. Solids (A) have a definite shape
and volume. Gases (C) have neither a definite shape nor volume.
**6.** Which of the following is a physical property?
A) Flammability
B) Reactivity with acid
C) Boiling point
D) Ability to rust
**Correct Answer:** C) Boiling point
**Rationale:** A physical property can be observed without changing the
substance's chemical identity. Boiling point, melting point, density, and color
are physical properties. Flammability (A), reactivity (B), and rusting (D) are
chemical properties.
