Question

Why aren't noble gases reactively ?

Answer 1

They are extremely unreactive, because their OUTER shell has 8 electrons (or 2 for helium) on it, meaning that it is filled to capacity. This, in turn, makes the atoms of the noble gases very stable in their electronic structure, so they are unreactive. All atoms react with others in order to achieve this stability.

Answer 2

Because noble gases  already have full shells of electrons therefore meaning they do not need to react to form anything.Whereas if they had 1 electron short of full shells , they would become VERY reactive.