Question

How many unpaired electrons are present in the ground state of Fe3+(z = 26 ), Mn2+ (25) and Neon (z= 10).

Answer 1

Explanation:

For determining the unpaired electrons remember that you need to remove the electrons from the highest 'n' (principal quantum number ) so here we go

1. Fe (z=26)

Fe = 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁶

removing 3 electrons from 4s and 3d because 4s can't remove more than 2

so now Fe3+ = 1s² 2s² 2p⁶ 3s² 3p⁶ 4s⁰ 3d⁵

as in d orbital only 10 electrons can be accommodated

let's see

Out of those 10 5 will be of one spin and 5 of opposite spin

So 5 unpaired electrons

Mn (z= 25)

Mn= 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁵

removing 2 electrons from 4s orbital

Mn2+ = 1s² 2s² 2p⁶ 3s² 3p⁶ 4s⁰ 3d⁵

here also 5 unpaired

Neon =1s² 2s² 2p⁶

no unpaired as it's an inert gas

Thank u ☺️