CHEM 210 Module 2 Exam (Portage Learning 2024/2025) — 30 High-Level actual Questions with 100% Correct Answers

CHEM 210 Module 2 Exam (Portage Learning
2024/2025) — 30 High-Level actual Questions with
100% Correct Answers

1.​ Which set of quantum numbers (n, l, m_l, m_s) is VALID for an electron in a
ground-state arsenic atom?​
A. 4, 2, −3, +½​
B. 3, 1, 0, −½​
C. 3, 3, 1, +½​
D. 2, 0, 1, −½


Correct Answer: B


Explanation: l must be ≤ n − 1 and |m_l| ≤ l. Only B (3,1,0,−½) satisfies all rules for a 3p
electron.


2.​ The first ionization energy of aluminum is 578 kJ mol⁻¹. What is the minimum
frequency (in Hz) of a photon that can ionize a SINGLE Al atom?​
A. 1.45 × 10¹⁵​
B. 2.90 × 10¹⁴​
C. 8.70 × 10¹⁴​
D. 1.16 × 10¹⁵


Correct Answer: A


Calculation: E = 578 × 10³ J / 6.022 × 10²³ = 9.60 × 10⁻¹⁹ J; ν = E/h = 9.60 × 10⁻¹⁹ / 6.626
× 10⁻³⁴ = 1.45 × 10¹⁵ Hz.

, 3.​ Arrange the following ions in order of DECREASING ionic radius: Mg²⁺, Na⁺, F⁻,
O²⁻.​
A. O²⁻ > F⁻ > Na⁺ > Mg²⁺​
B. Mg²⁺ > Na⁺ > F⁻ > O²⁻​
C. Na⁺ > Mg²⁺ > O²⁻ > F⁻​
D. F⁻ > O²⁻ > Mg²⁺ > Na⁺


Correct Answer: A


Explanation: All are isoelectronic (10 e⁻); radius increases as nuclear charge decreases
(O²⁻ 8 p⁺ → Mg²⁺ 12 p⁺).


4.​ How many nodes (total) does a 4d orbital possess?​
A. 3​
B. 4​
C. 5​
D. 2


Correct Answer: B


Explanation: Total nodes = n − 1 = 4 − 1 = 3 radial + 1 angular = 4.


5.​ Which pair of elements would form the MOST polar covalent bond?​
A. C—O​
B. N—Cl​
C. B—F​
D. Si—H


Correct Answer: C


Explanation: Largest ΔEN (B ≈ 2.04, F ≈ 3.98) ≈ 1.94 → most polar.