Answer: Option (A) is the correct answer.
Explanation:
Atomic number of helium is 2 and its electronic configuration is
. As here n = 1 this means that helium element belongs to period 1.
Since, helium atom has completely filled s-shell this means that it is unreactive in nature as it neither needs to lose or gain an electron in order to attain stability.
And, all the unreactive elements in the periodic table belongs to group 8A. That is why, helium also belongs to group 8A and period 1.
Thus, we can conclude that helium is located in Group 8A, Period 1
.