Question

In in nature there may not be an element for which the principal quantum number $n>4$, then the total possible number of elements will be

• A. $60$
• B. $32$
• C. $4$
• D. $64$

Answer 1

The correct option is A $60$

It is based on electronic configuration

$1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}4p^{6}4d^{10}4f^{14}$

Since maximum number of electrons which can be arranged is 60, thus there are 60 elements can be exists in nature if principle quantum number >4 were not allowed.