BRAINLIEST! :) The similarities and differences between the way electrons are filled in s and d subshells in groups 1B and 6B.

the 4s subshell in the third row of periodic table only fills first in the case of K and Ca atoms. However, the 3d subshell in transition metals and the main group elements after them is more stable than 4s and so fills first. Thus there is no scientific reason to write the electron configuration of transition elements as [Ar] 4s 3d and the correct form is [Ar] 3d 4s.

Have a good day

Explanation:

c. orbital shape i hope this is correct