Why are there 10 members of each d transition metal series?

Question

Why are there 10 members of each d transition metal series?

Answer 1

there are only 10 members because in period left to right atomic number incerases and hence after a certatin number when the D subshell is fully filled the electron has to go in S & P subshell hence it ends and P Blocks(general cofig. ns^2 np^1-6

Similarly The First 2 Gropus Are Having Electrons Only in  S Orbital that's Why they are refferd as S block elements (Alkali Metals And Alkaline earth Metals)( General Config. ns^1-2)

Answer 2

Transition metals correspond to the filling of a subshell d which is NOT a valence subshell and is always intern .A subshell d corresponding to second quantique number contains 10 electrons  

Answer 3

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