Which term describes a Lewis base?

A Lewis base is defined as an electron pair donor. This means that a Lewis base has the ability to donate a pair of electrons to form a covalent bond with an electron pair acceptor, also known as a Lewis acid. This characteristic distinguishes Lewis bases from other types of bases.

For example, in a reaction between ammonia (NH3), which acts as a Lewis base, and boron trifluoride (BF3), where BF3 is the Lewis acid, the ammonia donates a pair of electrons to the boron atom, resulting in a coordinate covalent bond. This fundamental understanding of Lewis bases emphasizes their role in chemical interactions where electron pair donation is critical.

In summary, the term for a Lewis base as an electron pair donor accurately captures its function in coordinate bond formation and distinguishes it from other types of acidic or basic behavior in chemical reactions.