Question

The atomic number of iron is 26

Its electronic configuration =2 8 8 8

Then how its valency is 2+ and3+

Answer 1

electronic configuration of iron=1s2,2s2, 2p6, 3s2, 3p6, 4s2, 3d6

when it loses 2 electrons from 4s subshell its valency is +2.
but when it loses 2 electrons from 4s along with one electron from 3d6 its valency becomes+3.


hence it has two valency .

hope it helps you