Ammonium Ion (NH4+): When ammonia accepts a proton (H+) from an acid, it forms the ammonium ion. This process makes ammonia behave as a base.
Weak Base: Ammonia is considered a weak base because it only partially dissociates in water and does not completely donate all its protons.
Lewis Base: A Lewis base refers to any species that can donate an electron pair. In terms of acids and bases, it specifically relates to substances that can donate electrons for bonding with other species.