CHEM 121 Foundations of General Chemistry Final Exam Prep
2026/2027 UPDATE
1. How many significant figures are in the measurement 0.004050 g?
A. 4
B. 3
C. 5
D. 6
Answer: A
Rationale: Leading zeros are never significant. Captive zeros and trailing zeros after a
decimal point are significant. Thus, 4, 0, 5, and 0 are significant.
2. Which of the following is an example of a physical change?
A. Ice melting
B. Burning wood
C. Iron rusting
D. Baking a cake
Answer: A
Rationale: Melting is a change of state, which is a physical change because the chemical
identity of water remains H2O.
,3. An object has a mass of 15.0 g and a volume of 3.0 mL. What is its density?
A. 5.0 g/mL
B. 0.20 g/mL
C. 45.0 g/mL
D. 18.0 g/mL
Answer: A
Rationale: Density = Mass / Volume. 15.0 g / 3.0 mL = 5.0 g/mL.
4. Convert 310 Kelvin to Celsius.
A. 583 °C
B. 37 °C
C. 25 °C
D. 100 °C
Answer: B
Rationale: Celsius = Kelvin - 273.15. 310 - 273 = 37.
5. Which state of matter has a definite volume but takes the shape of its
container?
A. Solid
B. Plasma
C. Gas
D. Liquid
Answer: D
Rationale: Liquids have a fixed volume but their particles move freely enough to take the
shape of the container.
, 6. What is the identity of an atom with 11 protons, 12 neutrons, and 11
electrons?
A. Magnesium
B. Aluminum
C. Sodium
D. Carbon
Answer: C
Rationale: The number of protons (atomic number) defines the element. Atomic number
11 is Sodium (Na).
7. Isotopes of the same element have:
A. The same number of neutrons but different number of protons
B. The same number of protons but different number of neutrons
C. Different numbers of both protons and neutrons
D. The same mass number
Answer: B
Rationale: Isotopes are atoms of the same element (same atomic number/protons) with
different mass numbers due to different neutron counts.
8. Which subatomic particle has a negligible mass and a negative charge?
A. Proton
B. Neutron
C. Nucleus
D. Electron
Answer: D
Rationale: Electrons have a charge of -1 and a mass approximately 1/1836th of a proton.
2026/2027 UPDATE
1. How many significant figures are in the measurement 0.004050 g?
A. 4
B. 3
C. 5
D. 6
Answer: A
Rationale: Leading zeros are never significant. Captive zeros and trailing zeros after a
decimal point are significant. Thus, 4, 0, 5, and 0 are significant.
2. Which of the following is an example of a physical change?
A. Ice melting
B. Burning wood
C. Iron rusting
D. Baking a cake
Answer: A
Rationale: Melting is a change of state, which is a physical change because the chemical
identity of water remains H2O.
,3. An object has a mass of 15.0 g and a volume of 3.0 mL. What is its density?
A. 5.0 g/mL
B. 0.20 g/mL
C. 45.0 g/mL
D. 18.0 g/mL
Answer: A
Rationale: Density = Mass / Volume. 15.0 g / 3.0 mL = 5.0 g/mL.
4. Convert 310 Kelvin to Celsius.
A. 583 °C
B. 37 °C
C. 25 °C
D. 100 °C
Answer: B
Rationale: Celsius = Kelvin - 273.15. 310 - 273 = 37.
5. Which state of matter has a definite volume but takes the shape of its
container?
A. Solid
B. Plasma
C. Gas
D. Liquid
Answer: D
Rationale: Liquids have a fixed volume but their particles move freely enough to take the
shape of the container.
, 6. What is the identity of an atom with 11 protons, 12 neutrons, and 11
electrons?
A. Magnesium
B. Aluminum
C. Sodium
D. Carbon
Answer: C
Rationale: The number of protons (atomic number) defines the element. Atomic number
11 is Sodium (Na).
7. Isotopes of the same element have:
A. The same number of neutrons but different number of protons
B. The same number of protons but different number of neutrons
C. Different numbers of both protons and neutrons
D. The same mass number
Answer: B
Rationale: Isotopes are atoms of the same element (same atomic number/protons) with
different mass numbers due to different neutron counts.
8. Which subatomic particle has a negligible mass and a negative charge?
A. Proton
B. Neutron
C. Nucleus
D. Electron
Answer: D
Rationale: Electrons have a charge of -1 and a mass approximately 1/1836th of a proton.
