The strength of a Brønsted-Lowry acid depends on how much the acid dissociates to form protons and on the strength of the conjugate base that the acid forms. Among two or more Brønsted-Lowry acids in a reaction, the one that reacts to form the most stable, or weakest, conjugate base is the one that most readily releases a proton (H⊕) and is therefore the stronger acid. The strength of a Lewis acid depends on how strongly the acid attracts a pair of electrons. The strength of most bases, either Brønsted-Lowry or Lewis bases depends on the availability of a pair of nonbonding electrons. The more loosely the base holds that pair of electrons, the stronger it is.