Question

why do helium, neon and argon have a zero .​

Answer 1

Explanation:

Helium has two electrons in its only energy shell. ... As the elements have the maximum number of electrons in their valence shells (thereby achieving stable duplet and octet configurations), they do not have any tendency to combine with other elements. Hence, Helium, Neon, and Argon have zero valency.

Answer 2

Explanation:

Helium has two electrons in its only energy shell. ... As the elements have the maximum number of electrons in their valence shells (thereby achieving stable duplet and octet configurations), they do not have any tendency to combine with other elements. Hence, Helium, Neon, and Argon have zero valency.