sir i have a doubt which is mentioned below
Electrons are filled in the sub shells of atom according to Hund’s rule, according to him- orbitals of the same energy are each filled with one electron before filling any with a second.
Orbital order-1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p, 8s.
And electronic filling sequence of cobalt in sub shell is- 1s2, 2s2, 2p6, 3s2, 3p6, 3d7, 4s2.
According to this electronic configuration is-2, 8, 17, 2