StraighterLine Chemistry Final Exam 2026/2027 – Verified Questions & Complete Solutions (A+ Study Guide)

StraighterLine Chemistry Final Exam
2026/2027 – Verified Questions & Complete
Solutions (A+ Study Guide)
This study guide contains 300 verified multiple-choice questions designed to
prepare you for the StraighterLine Chemistry Final Exam — work through each
question independently before checking the CORRECT ANSWER and EXPERT
RATIONALE below it.



STRAIGHTER LINE CHEMISTRY FINAL EXAM 2026/2027 300 QUESTIONS —
COMPLETE SOLUTIONS STUDY GUIDE



Question 1. What is the atomic number of Carbon?

A) 8

B) 10

C) 6

D) 12

E) 4

CORRECT ANSWER: C) 6

EXPERT RATIONALE: The atomic number represents the number of protons in
an atom's nucleus. Carbon has 6 protons, giving it atomic number 6 on the periodic
table.



Question 2. Which subatomic particle has a negative charge?

A) Proton

B) Neutron

C) Positron

D) Nucleus

,E) Electron

CORRECT ANSWER: E) Electron

EXPERT RATIONALE: Electrons carry a negative charge of –1. Protons are
positive (+1) and neutrons are neutral (0).



Question 3. The mass number of an atom is defined as:

A) Number of electrons only

B) Number of protons only

C) Number of neutrons only

D) Number of electrons plus protons

E) Number of protons plus neutrons

CORRECT ANSWER: E) Number of protons plus neutrons

EXPERT RATIONALE: Mass number = protons + neutrons. Electrons have
negligible mass and are not included in this calculation.



Question 4. Isotopes of the same element differ in their number of:

A) Protons

B) Electrons

C) Atomic numbers

D) Chemical properties

E) Neutrons

CORRECT ANSWER: E) Neutrons

EXPERT RATIONALE: Isotopes have the same number of protons (same
element) but different numbers of neutrons, giving them different mass numbers.

,Question 5. Which scientist proposed the nuclear model of the atom?

A) John Dalton

B) J.J. Thomson

C) Niels Bohr

D) Erwin Schrödinger

E) Ernest Rutherford

CORRECT ANSWER: E) Ernest Rutherford

EXPERT RATIONALE: Rutherford's gold foil experiment led him to conclude that
atoms have a small, dense, positively charged nucleus surrounded by empty space.



Question 6. What is the maximum number of electrons in the second energy
level?

A) 2

B) 6

C) 10

D) 18

E) 8

CORRECT ANSWER: E) 8

EXPERT RATIONALE: The second energy level contains the 2s and 2p subshells,
holding 2 + 6 = 8 electrons maximum.



Question 7. Which quantum number describes the shape of an orbital?

A) Principal quantum number (n)

B) Magnetic quantum number (mℓ)

C) Spin quantum number (ms)

, D) Mass quantum number

E) Angular momentum quantum number (ℓ)

CORRECT ANSWER: E) Angular momentum quantum number (ℓ)

EXPERT RATIONALE: The angular momentum quantum number (ℓ) defines the
shape of the orbital: ℓ=0 is s (spherical), ℓ=1 is p (dumbbell), ℓ=2 is d, etc.



Question 8. How many orbitals are in the 3d subshell?

A) 1

B) 3

C) 7

D) 9

E) 5

CORRECT ANSWER: E) 5

EXPERT RATIONALE: The d subshell has ℓ = 2, so mℓ = –2, –1, 0, +1, +2, giving 5
orbitals, each holding up to 2 electrons for a maximum of 10 electrons.



Question 9. The Pauli Exclusion Principle states that:

A) Electrons fill the lowest energy orbitals first

B) Electrons occupy separate orbitals before pairing

C) Energy is quantized in an atom

D) Atoms of the same element are identical

E) No two electrons in an atom can have the same four quantum numbers

CORRECT ANSWER: E) No two electrons in an atom can have the same
four quantum numbers