Question

How many unpaired electrons are present in the ground state of – 

1. Cr³⁺ (Z = 24) 

2. Ne (Z = 10)

Answer 1

1. Cr³⁺ (Z = 24) 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s¹ 

Cr³⁺ – 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁴ . 

It contains 4 unpaired electrons. 

2. Ne (Z = 10) 1s² 2s² 2p⁶ 

No unpaired electrons in it.