Question

Why copper(I) is diamagnetic but copper(II) is paramagnetic?

Answer 1

A substance is paramagnetic when it has at least one unpaired electron and a substance is diamagnetic when it has no unpaired electron

In case of of Cu(I) configuration is [Ar] 3d10
3d10
xx
xx
xx
xx
xx

As there is no unpaired electron in Cu(I), therefore Cu(I) is diamagnetic in nature.

On the other hand in Cu(II) the configuration of Cu(II) is [Ar] 3d9
3d9
xx
xx
xx
xx
x

It has one unpaired electron in one of its orbital. So, Cu(II) is paramagnetic.

Answer 2

Answer:

Cobalt I is diamagnetic

Explanation:

If cobalt has oxidation state +1 It means that d orbital is completely field and All will be in pairs and we know that all pairs will be Diamagnetic