CHEM 103: General Chemistry I —
Portage Learning | Module 1–6 Exams
& Final Exam | 2025/2026 Verified
Questions & Correct Answers
Real Exam-Based Questions and Verified Answers | 100% Accuracy | Portage Learning
Chemistry Exam | Graded A+
Introduction
This comprehensive resource includes 150 official-style multiple-choice questions with
verified correct answers for the CHEM 103: General Chemistry I course by Portage
Learning, covering Modules 1 through 6 and the Final Exam for the 2025/2026
academic year. Topics include atomic structure, chemical bonding, stoichiometry,
thermochemistry, periodic trends, gas laws, and solution chemistry. Designed for
students seeking to master the course content and excel in assessments, this guide mirrors the
Portage Learning exam format (typically 25–30 questions per module exam and 50–60 for the
final). Questions are verified for 100% accuracy, ensuring confident preparation for a Graded A+
outcome.
Answer Format
All correct answers are clearly marked in bold and green for efficient review and confident
preparation.
CHEM 103 Portage Learning Practice Test |
2025/2026 Verified 150 Q&A
Module 1: Basic Concepts and Atomic Structure
1. What is the number of protons in an atom of Carbon-12?
a) 6
,b) 12
c) 14
d) 18
a) 6
Rationale: Carbon’s atomic number is 6, indicating 6 protons, regardless of the isotope.
2. Which subatomic particle has a negligible mass and a negative charge?
a) Proton
b) Neutron
c) Electron
d) Nucleus
c) Electron
Rationale: Electrons have a mass of approximately 1/1836 amu and a negative charge.
3. How many neutrons are in an atom of Oxygen-16?
a) 6
b) 8
c) 10
d) 16
b) 8
Rationale: Oxygen-16 has a mass number of 16 and atomic number of 8, so neutrons = 16 - 8 =
8.
4. The atomic mass unit (amu) is based on which isotope?
a) Hydrogen-1
b) Carbon-12
c) Oxygen-16
d) Nitrogen-14
b) Carbon-12
Rationale: 1 amu is defined as 1/12 the mass of a Carbon-12 atom.
5. Which element has the electron configuration 1s² 2s² 2p⁶ 3s²?
a) Sodium
b) Magnesium
c) Aluminum
d) Silicon
b) Magnesium
Rationale: The configuration has 12 electrons, corresponding to Magnesium (atomic number
12).
6. What is the mass number of an atom with 17 protons and 18 neutrons?
a) 17
b) 18
c) 35
d) 52
, c) 35
Rationale: Mass number = protons + neutrons = 17 + 18 = 35.
7. An atom with 8 protons and 8 neutrons is an isotope of:
a) Nitrogen
b) Oxygen
c) Fluorine
d) Neon
b) Oxygen
Rationale: Oxygen has 8 protons; this is Oxygen-16 (8 protons + 8 neutrons).
8. The number of electrons in a neutral atom of Sulfur is:
a) 16
b) 32
c) 8
d) 18
a) 16
Rationale: Sulfur’s atomic number is 16, indicating 16 electrons in a neutral atom.
9. Which quantum number describes the shape of an orbital?
a) Principal
b) Azimuthal
c) Magnetic
d) Spin
b) Azimuthal
Rationale: The azimuthal quantum number (l) defines the orbital’s shape (s, p, d, etc.).
10. How many orbitals are in the 3p subshell?
a) 1
b) 3
c) 5
d) 7
b) 3
Rationale: The p subshell has 3 orbitals (px, py, pz).
11. The maximum number of electrons in the n=2 energy level is:
a) 2
b) 4
c) 8
d) 18
c) 8
Rationale: Maximum electrons = 2n² = 2(2)² = 8.
12. Which element has the electron configuration [Ar] 4s¹?
a) Calcium
b) Potassium
Portage Learning | Module 1–6 Exams
& Final Exam | 2025/2026 Verified
Questions & Correct Answers
Real Exam-Based Questions and Verified Answers | 100% Accuracy | Portage Learning
Chemistry Exam | Graded A+
Introduction
This comprehensive resource includes 150 official-style multiple-choice questions with
verified correct answers for the CHEM 103: General Chemistry I course by Portage
Learning, covering Modules 1 through 6 and the Final Exam for the 2025/2026
academic year. Topics include atomic structure, chemical bonding, stoichiometry,
thermochemistry, periodic trends, gas laws, and solution chemistry. Designed for
students seeking to master the course content and excel in assessments, this guide mirrors the
Portage Learning exam format (typically 25–30 questions per module exam and 50–60 for the
final). Questions are verified for 100% accuracy, ensuring confident preparation for a Graded A+
outcome.
Answer Format
All correct answers are clearly marked in bold and green for efficient review and confident
preparation.
CHEM 103 Portage Learning Practice Test |
2025/2026 Verified 150 Q&A
Module 1: Basic Concepts and Atomic Structure
1. What is the number of protons in an atom of Carbon-12?
a) 6
,b) 12
c) 14
d) 18
a) 6
Rationale: Carbon’s atomic number is 6, indicating 6 protons, regardless of the isotope.
2. Which subatomic particle has a negligible mass and a negative charge?
a) Proton
b) Neutron
c) Electron
d) Nucleus
c) Electron
Rationale: Electrons have a mass of approximately 1/1836 amu and a negative charge.
3. How many neutrons are in an atom of Oxygen-16?
a) 6
b) 8
c) 10
d) 16
b) 8
Rationale: Oxygen-16 has a mass number of 16 and atomic number of 8, so neutrons = 16 - 8 =
8.
4. The atomic mass unit (amu) is based on which isotope?
a) Hydrogen-1
b) Carbon-12
c) Oxygen-16
d) Nitrogen-14
b) Carbon-12
Rationale: 1 amu is defined as 1/12 the mass of a Carbon-12 atom.
5. Which element has the electron configuration 1s² 2s² 2p⁶ 3s²?
a) Sodium
b) Magnesium
c) Aluminum
d) Silicon
b) Magnesium
Rationale: The configuration has 12 electrons, corresponding to Magnesium (atomic number
12).
6. What is the mass number of an atom with 17 protons and 18 neutrons?
a) 17
b) 18
c) 35
d) 52
, c) 35
Rationale: Mass number = protons + neutrons = 17 + 18 = 35.
7. An atom with 8 protons and 8 neutrons is an isotope of:
a) Nitrogen
b) Oxygen
c) Fluorine
d) Neon
b) Oxygen
Rationale: Oxygen has 8 protons; this is Oxygen-16 (8 protons + 8 neutrons).
8. The number of electrons in a neutral atom of Sulfur is:
a) 16
b) 32
c) 8
d) 18
a) 16
Rationale: Sulfur’s atomic number is 16, indicating 16 electrons in a neutral atom.
9. Which quantum number describes the shape of an orbital?
a) Principal
b) Azimuthal
c) Magnetic
d) Spin
b) Azimuthal
Rationale: The azimuthal quantum number (l) defines the orbital’s shape (s, p, d, etc.).
10. How many orbitals are in the 3p subshell?
a) 1
b) 3
c) 5
d) 7
b) 3
Rationale: The p subshell has 3 orbitals (px, py, pz).
11. The maximum number of electrons in the n=2 energy level is:
a) 2
b) 4
c) 8
d) 18
c) 8
Rationale: Maximum electrons = 2n² = 2(2)² = 8.
12. Which element has the electron configuration [Ar] 4s¹?
a) Calcium
b) Potassium
