Why does carbonate have a valence of two?

1 Answer
Nov 12, 2016

Answer:

The valency of carbonate is two because it can combine with two hydrogen atoms.

Explanation:

Valency is the number of univalent atoms (e.g., #"H"# or #"Cl"# atoms) that can combine with an atom or an ion.

The structure of carbonate is

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Each #"O"# atom has a negative charge, so it can combine with an #"H"^"+"# ion to form carbonic acid.

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Since carbonate can combine with two #"H"# atoms, its valency is two.