Question

why do we helium neon organ have zone valency.

Answer 1

Helium, Neon and Argon have zero valency because they have their outer shell completely filled and are called noble gas and chemically inert gas. Due to they have completely filled outer shell they do not lose or gain electron in a chemical reaction. So their valency is zero.

Answer 2

Helium, neon, argon have zero valency because they have complete electrons their outermost shell