Page "Acid" Paragraph 4

In chemistry, the Lewis definition of acidity is frequently encountered.

Lewis acids are electron-pair acceptors.

Examples of Lewis acids include all metal cations, and electron-deficient molecules such as boron trifluoride and aluminium trichloride.

Hydronium ions are acids according to all three definitions.

Interestingly, although alcohols and amines can be Brønsted-Lowry acids as mentioned above, they can also function as Lewis bases due to the lone pairs of electrons on their oxygen and nitrogen atoms.