Question

The electronic configuration of the free manganese and copper atoms are [Ar]3d5 4s2 and [Ar]3d104s1 , respectively. What are the configurations of the free ions Mn4+ and Cu3+ ions ?

Answer 1

the electronic configuration of Mn4+ is [Ar]3d7
the electronic configuration of Cu3+ is [Ar]3d4

I THINK IT IS CORRECT

Answer 2

Manganese -Mn - Atomic number -25 -1s²2s²2p⁶3s²3p⁶4s²3d⁵ or [ Ar]4s²3d⁵
Copper-Cu- Atomic Number -29-1s²2s²2p⁶3s²3p⁶4s¹3d¹⁰ or [Ar]4s¹3d¹⁰

Now Mn⁴⁺ ion means 4 electrons are removed - 2 electrons from 4s sub shell  and 2 electrons  from 3d subshell.

So electronic configuration of Mn⁴⁺ ion is:  [ Ar]3d³

Now Cu⁺³ ion ---- 3 electrons are removed - one electron from 4s sub shell and 2 electrons from 3d sub shell.

So electronic configuration of Cu⁺³ ion is : [Ar] 3d⁸