CHEM134 Practice Exam 12 Nuclear
Chemistry Practice Exam Questions
And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A |
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1. Which statement best describes nuclear chemistry?
A. The study of chemical reactions involving only valence electrons
B. The study of physical changes involving phase transitions
C. The study of changes involving atomic nuclei and nuclear
radiation
D. The study of intermolecular forces in molecular compounds
Answer: C. The study of changes involving atomic nuclei and
nuclear radiation
Rationale: Nuclear chemistry focuses on processes that alter atomic
nuclei, including radioactive decay, nuclear reactions, fission, fusion,
and associated energy changes. Ordinary chemical reactions primarily
involve electrons, whereas nuclear processes can change the identity
of an element and release vastly larger amounts of energy.
2. What distinguishes a nuclear reaction from an ordinary chemical
reaction?
A. Nuclear reactions involve changes in the nucleus
B. Nuclear reactions can change one element into another
C. Nuclear reactions always require oxygen
D. Nuclear reactions occur only in aqueous solutions
,Answer: B. Nuclear reactions can change one element into another
Rationale: A nuclear reaction can alter the number of protons in a
nucleus, thereby producing a different element. Chemical reactions
rearrange electrons and chemical bonds but normally leave the nuclei
unchanged.
3. What is an isotope?
A. An atom having a different number of electrons than protons
B. An atom having no neutrons
C. An atom with a different atomic number but identical mass number
D. Atoms of the same element having different numbers of neutrons
Answer: D. Atoms of the same element having different numbers of
neutrons
Rationale: Isotopes have the same atomic number because they contain
the same number of protons, but they differ in neutron number.
Consequently, isotopes of an element have different mass numbers
while retaining essentially the same chemical identity.
4. Which particle determines the atomic number of an element?
A. Proton
B. Neutron
C. Electron
D. Alpha particle
Answer: A. Proton
Rationale: The atomic number is defined as the number of protons in
the nucleus. Because each element has a unique proton number,
changing the number of protons changes the identity of the element.
, 5. Which notation correctly represents a nuclide containing 17
protons and 18 neutrons?
A. ³⁵₁₈Ar
B. ³⁵₁₇Cl
C. ³⁶₁₇Cl
D. ¹⁷₃₅Cl
Answer: B. ³⁵₁₇Cl
Rationale: The atomic number is the number of protons, so Z = 17.
The mass number equals protons plus neutrons, giving A = 17 + 18 =
35. Atomic number 17 corresponds to chlorine, so the nuclide is ³⁵₁₇Cl.
6. A nucleus contains 92 protons and 143 neutrons. What is its mass
number?
A. 51
B. 92
C. 235
D. 143
Answer: C. 235
Rationale: Mass number is the total number of protons and neutrons
in the nucleus. Therefore, A = 92 + 143 = 235. The electrons are not
included in the mass number.
7. Which symbol represents an alpha particle?
A. ⁰₋₁e
B. ¹₀n
C. ⁰₊₁e
D. ⁴₂He
Answer: D. ⁴₂He
, Rationale: An alpha particle consists of two protons and two neutrons,
making it equivalent to a helium-4 nucleus. Its nuclear notation is
⁴₂He, and it carries a +2 charge.
8. What is the charge of an alpha particle?
A. +2
B. +1
C. 0
D. −1
Answer: A. +2
Rationale: An alpha particle contains two protons and no electrons.
Since each proton carries a +1 charge, the alpha particle has a net
charge of +2.
9. Which type of nuclear radiation consists of high-energy
electromagnetic radiation?
A. Alpha radiation
B. Beta radiation
C. Gamma radiation
D. Neutron radiation
Answer: C. Gamma radiation
Rationale: Gamma radiation consists of high-energy photons. Unlike
alpha and beta radiation, gamma radiation has no mass and no
electrical charge. It is electromagnetic radiation with very high
frequency and energy.
10. Which nuclear particle is emitted during beta-minus decay?
A. Alpha particle
B. Electron
Chemistry Practice Exam Questions
And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A |
Instant Download Pdf
1. Which statement best describes nuclear chemistry?
A. The study of chemical reactions involving only valence electrons
B. The study of physical changes involving phase transitions
C. The study of changes involving atomic nuclei and nuclear
radiation
D. The study of intermolecular forces in molecular compounds
Answer: C. The study of changes involving atomic nuclei and
nuclear radiation
Rationale: Nuclear chemistry focuses on processes that alter atomic
nuclei, including radioactive decay, nuclear reactions, fission, fusion,
and associated energy changes. Ordinary chemical reactions primarily
involve electrons, whereas nuclear processes can change the identity
of an element and release vastly larger amounts of energy.
2. What distinguishes a nuclear reaction from an ordinary chemical
reaction?
A. Nuclear reactions involve changes in the nucleus
B. Nuclear reactions can change one element into another
C. Nuclear reactions always require oxygen
D. Nuclear reactions occur only in aqueous solutions
,Answer: B. Nuclear reactions can change one element into another
Rationale: A nuclear reaction can alter the number of protons in a
nucleus, thereby producing a different element. Chemical reactions
rearrange electrons and chemical bonds but normally leave the nuclei
unchanged.
3. What is an isotope?
A. An atom having a different number of electrons than protons
B. An atom having no neutrons
C. An atom with a different atomic number but identical mass number
D. Atoms of the same element having different numbers of neutrons
Answer: D. Atoms of the same element having different numbers of
neutrons
Rationale: Isotopes have the same atomic number because they contain
the same number of protons, but they differ in neutron number.
Consequently, isotopes of an element have different mass numbers
while retaining essentially the same chemical identity.
4. Which particle determines the atomic number of an element?
A. Proton
B. Neutron
C. Electron
D. Alpha particle
Answer: A. Proton
Rationale: The atomic number is defined as the number of protons in
the nucleus. Because each element has a unique proton number,
changing the number of protons changes the identity of the element.
, 5. Which notation correctly represents a nuclide containing 17
protons and 18 neutrons?
A. ³⁵₁₈Ar
B. ³⁵₁₇Cl
C. ³⁶₁₇Cl
D. ¹⁷₃₅Cl
Answer: B. ³⁵₁₇Cl
Rationale: The atomic number is the number of protons, so Z = 17.
The mass number equals protons plus neutrons, giving A = 17 + 18 =
35. Atomic number 17 corresponds to chlorine, so the nuclide is ³⁵₁₇Cl.
6. A nucleus contains 92 protons and 143 neutrons. What is its mass
number?
A. 51
B. 92
C. 235
D. 143
Answer: C. 235
Rationale: Mass number is the total number of protons and neutrons
in the nucleus. Therefore, A = 92 + 143 = 235. The electrons are not
included in the mass number.
7. Which symbol represents an alpha particle?
A. ⁰₋₁e
B. ¹₀n
C. ⁰₊₁e
D. ⁴₂He
Answer: D. ⁴₂He
, Rationale: An alpha particle consists of two protons and two neutrons,
making it equivalent to a helium-4 nucleus. Its nuclear notation is
⁴₂He, and it carries a +2 charge.
8. What is the charge of an alpha particle?
A. +2
B. +1
C. 0
D. −1
Answer: A. +2
Rationale: An alpha particle contains two protons and no electrons.
Since each proton carries a +1 charge, the alpha particle has a net
charge of +2.
9. Which type of nuclear radiation consists of high-energy
electromagnetic radiation?
A. Alpha radiation
B. Beta radiation
C. Gamma radiation
D. Neutron radiation
Answer: C. Gamma radiation
Rationale: Gamma radiation consists of high-energy photons. Unlike
alpha and beta radiation, gamma radiation has no mass and no
electrical charge. It is electromagnetic radiation with very high
frequency and energy.
10. Which nuclear particle is emitted during beta-minus decay?
A. Alpha particle
B. Electron
