In a new theory submitted in 1923 independently by Brønsted and Lowry, an acid is defined as a molecule or an ion which gives H+ and a molecule or ion that receives H+ from a partner is a base. A base is not only a molecule or an ion which gives OH but anything which receives H+. Since the acid HA gives H+ to water in an aqueous solution and generates an oxonium ion, H3O+
, water is also a kind of base according to this definition.