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Atomic Structure — JEE Main Chemistry PYQ MCQs with Solutions
Free JEE Main Chemistry PYQ Atomic Structure MCQs with step-by-step solutions. Practise online on Prepizo — no login needed.
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Sample questions with solutions
Q1 — easy
The number of electrons that can be accommodated in the M shell is:
A. 8
B. 32
C. 12
D. 18 ✓ Correct
Solution: The M shell corresponds to n=3. Maximum electrons = 2n² = 2(3)² = 18
Q2 — easy
Which of the following orbitals has the highest energy in a hydrogen atom?
A. 1s
B. 2s
C. 2p
D. 3s ✓ Correct
Solution: In hydrogen, energy increases with principal quantum number (n). n=3 has the highest energy.
Q3 — medium
The spin quantum number of an electron can have values:
A. 0, ±1/2, ±1
B. 0, +1/2, -1/2
C. +1/2, -1/2 ✓ Correct
D. 0, 1
Solution: Spin quantum number (s) can only have two values: +1/2 (spin up) or -1/2 (spin down).
Q4 — medium
Which of the following correctly represents the electronic configuration of Cu?
A. [Ar] 3d¹¹ 4s⁰
B. [Ar] 3d⁹ 4s²
C. [Ar] 3d⁸ 4s²
D. [Ar] 3d¹⁰ 4s¹ ✓ Correct
Solution: Copper is an exception to Aufbau principle. It has configuration [Ar] 3d¹⁰ 4s¹ for stability.