Question

Element X is a metal with a valency of 2, and Y is 3 non-metal with a valency of 3.

Write an equation to show how Y forms an ion.

Answer 1

Valency: Valency of an atom is defined as the number of electrons gained or lost by an atom to attain noble gas electronic configuration.

• A metal losses electrons to form a neutral atom whereas a non-metal gains electrons.
• As the valency of Y is 3.
• Y, being a non-metal gains three electrons and forms $Y^{3-}$ anion.
• The chemical equation can be represented as:

$\underset{\mathrm{Non}\mathrm{metal}}{\mathrm{Y}}+\underset{\mathrm{electrons}}{3{\mathrm{e}}^{-}}\to \underset{\mathrm{Non}\mathrm{metal}\mathrm{anion}}{{\mathrm{Y}}^{3-}}$