The atomic number of Unnilunium is $...........$

In the sixth period,the orbitals being filled are :-

Who developed the long form of periodic table?

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 $n = 6$

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

In which of the following groups would placing Helium satisfy all its properties?