Here's why:
* Lewis Base: A Lewis base is a species that donates an electron pair.
* Ammonia's Lone Pair: Ammonia has a lone pair of electrons on the nitrogen atom.
* Covalent Bond Formation: When ammonia forms a covalent bond, it shares its lone pair with another atom, effectively donating the electron pair.
Example: In the reaction of ammonia with hydrogen chloride (HCl), ammonia acts as a Lewis base by donating its lone pair to the hydrogen ion (H⁺) from HCl. This forms an ammonium ion (NH₄⁺) and a chloride ion (Cl⁻).
NH₃ + HCl → NH₄⁺ + Cl⁻
