Determine the position of the element in the periodic table for the following outer electronic configurations:
$(i)$ $ns^2 np^4$ where $n = 3$
$(ii)$ $(n-1)d^2 ns^2$ where $n = 4$
$(iii)$ $(n-2)f^7 (n-1)d^1 ns^2$ where $n = 6$

(N/A) $(i)$ For $n=3$,the element belongs to the $3^{rd}$ period.
Total valence electrons = $2+4 = 6$. Therefore,it belongs to group $16$ ($p$-block element).
$(ii)$ For $n=4$,the element belongs to the $4^{th}$ period.
The configuration is $3d^2 4s^2$. Total valence electrons = $2+2 = 4$. Therefore,it belongs to group $4$ ($d$-block element).
$(iii)$ For $n=6$,the element belongs to the $6^{th}$ period.
The configuration is $4f^7 5d^1 6s^2$. Since the last electron enters the $f$-orbital,it is an $f$-block element (Lanthanoid series).
All $f$-block elements belong to group $3$.