,CHEM 103 Module 2 | Practice Q&A | 2026/2027 | Chemistry |
Portage Learning | 100% PASS
1. What is the atomic number of an atom?
A) The number of protons in the nucleus
B) The number of neutrons in the nucleus
C) The number of protons plus neutrons
D) The number of electrons in the outermost shell
Correct Answer: The number of protons in the nucleus
Rationale: The atomic number (Z) is the number of protons in the nucleus of
an atom. It uniquely identifies an element and determines its position on the
periodic table.
2. What is the mass number of an atom?
A) The number of protons
B) The number of electrons
C) The number of protons plus neutrons
D) The number of neutrons
Correct Answer: The number of protons plus neutrons
Rationale: The mass number (A) is the sum of the number of protons and
neutrons in the nucleus of an atom. It is a whole number that identifies a
specific isotope.
3. How many protons, neutrons, and electrons are in a neutral atom of ⁶⁵Cu
(copper-65)?
A) 29 protons, 36 neutrons, 29 electrons
,B) 29 protons, 65 neutrons, 29 electrons
C) 36 protons, 29 neutrons, 36 electrons
D) 65 protons, 0 neutrons, 65 electrons
Correct Answer: 29 protons, 36 neutrons, 29 electrons
Rationale: Copper has an atomic number of 29, so it has 29 protons and 29
electrons in a neutral atom. The mass number is 65, so neutrons = 65 - 29 =
36.
4. How many protons, neutrons, and electrons are in a neutral atom of ⁷⁵As
(arsenic-75)?
A) 33 protons, 42 neutrons, 33 electrons
B) 33 protons, 75 neutrons, 33 electrons
C) 42 protons, 33 neutrons, 42 electrons
D) 75 protons, 0 neutrons, 75 electrons
Correct Answer: 33 protons, 42 neutrons, 33 electrons
Rationale: Arsenic has an atomic number of 33, so it has 33 protons and 33
electrons in a neutral atom. The mass number is 75, so neutrons = 75 - 33 =
42.
5. Which subatomic particle has a relative mass of approximately 1 amu and
a +1 charge?
A) Electron
B) Neutron
C) Proton
D) Positron
, Correct Answer: Proton
Rationale: Protons have a relative mass of approximately 1 atomic mass unit
(amu) and a +1 charge. Neutrons have approximately 1 amu and no charge.
Electrons have negligible mass and a -1 charge.
6. Which subatomic particle has a relative mass of approximately 1 amu and
no charge?
A) Proton
B) Neutron
C) Electron
D) Positron
Correct Answer: Neutron
Rationale: Neutrons have a relative mass of approximately 1 atomic mass
unit (amu) and no charge (neutral). Protons have a +1 charge, and electrons
have negligible mass and a -1 charge.
7. Which subatomic particle has a negligible mass and a -1 charge?
A) Proton
B) Neutron
C) Electron
D) Positron
Correct Answer: Electron
Portage Learning | 100% PASS
1. What is the atomic number of an atom?
A) The number of protons in the nucleus
B) The number of neutrons in the nucleus
C) The number of protons plus neutrons
D) The number of electrons in the outermost shell
Correct Answer: The number of protons in the nucleus
Rationale: The atomic number (Z) is the number of protons in the nucleus of
an atom. It uniquely identifies an element and determines its position on the
periodic table.
2. What is the mass number of an atom?
A) The number of protons
B) The number of electrons
C) The number of protons plus neutrons
D) The number of neutrons
Correct Answer: The number of protons plus neutrons
Rationale: The mass number (A) is the sum of the number of protons and
neutrons in the nucleus of an atom. It is a whole number that identifies a
specific isotope.
3. How many protons, neutrons, and electrons are in a neutral atom of ⁶⁵Cu
(copper-65)?
A) 29 protons, 36 neutrons, 29 electrons
,B) 29 protons, 65 neutrons, 29 electrons
C) 36 protons, 29 neutrons, 36 electrons
D) 65 protons, 0 neutrons, 65 electrons
Correct Answer: 29 protons, 36 neutrons, 29 electrons
Rationale: Copper has an atomic number of 29, so it has 29 protons and 29
electrons in a neutral atom. The mass number is 65, so neutrons = 65 - 29 =
36.
4. How many protons, neutrons, and electrons are in a neutral atom of ⁷⁵As
(arsenic-75)?
A) 33 protons, 42 neutrons, 33 electrons
B) 33 protons, 75 neutrons, 33 electrons
C) 42 protons, 33 neutrons, 42 electrons
D) 75 protons, 0 neutrons, 75 electrons
Correct Answer: 33 protons, 42 neutrons, 33 electrons
Rationale: Arsenic has an atomic number of 33, so it has 33 protons and 33
electrons in a neutral atom. The mass number is 75, so neutrons = 75 - 33 =
42.
5. Which subatomic particle has a relative mass of approximately 1 amu and
a +1 charge?
A) Electron
B) Neutron
C) Proton
D) Positron
, Correct Answer: Proton
Rationale: Protons have a relative mass of approximately 1 atomic mass unit
(amu) and a +1 charge. Neutrons have approximately 1 amu and no charge.
Electrons have negligible mass and a -1 charge.
6. Which subatomic particle has a relative mass of approximately 1 amu and
no charge?
A) Proton
B) Neutron
C) Electron
D) Positron
Correct Answer: Neutron
Rationale: Neutrons have a relative mass of approximately 1 atomic mass
unit (amu) and no charge (neutral). Protons have a +1 charge, and electrons
have negligible mass and a -1 charge.
7. Which subatomic particle has a negligible mass and a -1 charge?
A) Proton
B) Neutron
C) Electron
D) Positron
Correct Answer: Electron
