Question

Why do Helium,Nein,Argon have zeor valency?

Answer 1

Basically, if an element has 8 electrons in its valence shell or 2 electrons in its only shell like helium it does not require anymore electron as its shell is already completed and hence it neithet loses nor gain electrons. ... Thus, their valency is zero.

Answer 2

Helium, neon, Argon have 0 valancy because they are stable. their s outermost orbit is fully completed