* Sulfite Ion: The sulfite ion has a formula of SO₃²⁻, meaning it has a charge of -2.
* Valency: Valency refers to the combining capacity of an atom or ion. It is the number of electrons an atom or ion can gain, lose, or share to form a chemical bond.
* Determining Valency: Since the sulfite ion has a charge of -2, it means it has gained two electrons to achieve stability. Therefore, its valency is 2.
Important Note: Valency is sometimes used interchangeably with oxidation state. While the valency of sulfite is 2, its oxidation state of the sulfur atom in sulfite is +4.
