Question

If the maximum permissible orbits of elements in nature are limited to $n=4$, what are the number of possible elements?

Answer 1

subshell	capacity of subshell	no of electrons	total no of electrons
s	2	4	$2\times 4=8$
p	6	3	18
d	10	2	20
f	14	1	14

Hence, the total number of electrons=60

This is the possible number of arrangement of electrons and hence the number of allowed elements