Azimuthal Quantum Number Electrons in Chromium | JEE Mains PYQ | Structure of Atom
Q. Consider the ground state of chromium atom (Z = 24). How many electrons are with azimuthal quantum number l = 1 and l = 2 respectively?
A. 16 and 5
B. 12 and 5
C. 12 and 4
D. 16 and 4
Explanation
Step 1: Write ground state electronic configuration of chromium

Chromium (Z = 24):
1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s¹

Step 2: Count electrons with l = 1 (p-orbitals)

p-orbitals have l = 1
2p⁶ + 3p⁶ = 12 electrons

Step 3: Count electrons with l = 2 (d-orbitals)

d-orbitals have l = 2
3d⁵ = 5 electrons

Correct Answer = 12 and 5

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