Helium has one shell (k) which requires two electrons and helium has two-electrons so the outermost shell is filled and helium has no need to lose electrons or gain electrons. Therefore the valency of helium is taken as zero. ... Hence the valency of noble gases is zero.

Why do helium and Argon has zero valency?

Answer: Valency is a combining capacity of an element. As there are no free electrons in the valence shell and the elements are already in a stable state, the noble gases' valency is zero.

Why does helium have no valence electrons?

Explanation: Helium is located in period 1, group 18 of the Periodic Table and has an atomic number equal to 2. As a result, neutral helium will only have 2 electrons surrounding its nucleus. ... Two electrons in its outermost (and only) shell, two valence electrons.