Question

In the periodic table hydrogen is placed in Group 1A (group 1) and helium is placed in Group 8A (group 18). The most likely reason for this is:

Answer 1

Answer:

This question appears incomplete

Explanation:

This question appears incomplete because of the absence of options. However, hydrogen is placed in group 1 because it has just one electron in it's outermost shell (which happens to be the only shell it has) just like every other group 1A/group 1 element. While helium is placed in group 8A/group 18 because it has a completely filled outermost shell (which is also the only shell it has) just like every other element in group 8A/group 18.