Question

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Why do helium, neon anú argon have zero valency?​

Answer 1

Answer:

they are called as Nobel gases and they have 0 valency

this is because they are already stable with 8 elctrons in their outer most shell. they don't need any more electrons or give their elctrons to any atom. they don't react with any element or involve in any chemical reaction..........

because of this all we say that they have 0 valency

i think this is the answer............I hope this helps u

Answer 2

Explanation:

Because their outer shell is fully filled.Valency is the no. of electrons that are needed to make the valency shell(outer shell) fully filled. As the outer shell is already filled they have zero valency