Question

Give one example of a polyvalent monoatomic anion.

Answer 1

Anion:

• It is defined as a negatively charged ion which is formed when an atom gains extra electron.
• Since the ion formed is having more number of electrons than protons, hence carries net negative charge.
• Example of anion is ${\mathrm{Cl}}^{-}$which is formed when chlorine atom is gains one extra electron to complete its octet.

Polyvalent anion:

• An atom in an ion having more than one valency and acquires a net negative charge of more than one is called a polyvalent anion.
• Example; oxide ion (${\mathrm{O}}^{2-}$), nitrate ion (${{\mathrm{NO}}_3}^{-}$) etc.

Monoatomic anion:

• An ion with net negative charge which consists of exactly one atom is called as monoatomic anion.
• Example; chloride ion (${\mathrm{Cl}}^{-}$), oxide ion (${\mathrm{O}}^{2-}$ ) etc.

Thus, the example of a polyvalent monoatomic anion is oxide ion (${\mathbf{O}}^{\mathbf{2}\mathbf{-}}$).