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Structure of the Atom — Science STD 9 — Question

CBSE BoardEnglish MediumSTD 9ScienceStructure of the Atom3 Marks
Question

Why do Helium, Neon and Argon have a zero valency?

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Answer

Helium has two electrons in its only energy shell. Argon and Neon have 8 electrons each in their valence shells. As the elements have the maximum number of electrons in their valence shells (thereby achieving duplet and octet configurations), they do not have any tendency to combine with other elements. Hence, Helium, Neon and Argon have zero valency.

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