Prove that according to quantum numbers,the $6^{th}$ period contains $32$ elements.

(N/A) For the $6^{th}$ period,the principal quantum number $n = 6$.
The orbitals available are determined by the values of $l$ from $0$ to $n-1$. For $n=6$,the subshells involved in filling the period are $6s$,$4f$,$5d$,and $6p$.

Subshell	$6s$	$4f$	$5d$	$6p$
Number of orbitals	$1$	$7$	$5$	$3$

Total number of orbitals $= 1 + 7 + 5 + 3 = 16$.
Since each orbital can hold a maximum of $2$ electrons,the total number of electrons $= 16 \times 2 = 32$.
Therefore,there are $32$ elements in the $6^{th}$ period.