Answer :
Answer:
Writing of the subshells
Explanation:
Given configuration:-
[tex]\\ \sf\longmapsto 1s^22s^22p^63s^23p^63d^{10}4s^2[/tex]
Actual configuration:-
[tex]\\ \sf\longmapsto 1s^22s^22p^63s^23p^64s^23d^{10}[/tex]
This is because 4s orbital is less in energy than that of 3d