Question

Predict the position in the periodic table

(n-l)d1 ns2 where n=4

(n-l) d2 ns2 where n=5

Answer 1

If n=4 then 3d1 4s2

the electronic configuration is

1s2 2s2 2p6 3s2 3p6 3d1 4s2

Atomic no=21
This is the first d block element scandium

If n=5 then 4d2 5s2

The electronic configuration is

1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d2 5s2

Atomic no=40
This is also a d block element Zirconium