The attraction between ammonia and water is even more striking. Water molecules dissociate spontaneously to a certain extent into protons and hydroxide ions:

H₂0 -----> H+ + OH-

When ammonia gas is dissolved in water, it competes with water for one of the water molecule's own hydrogen ions, and some of the protons released by dissociation of water are picked up by ammonia molecules:

NH₃ + H+ -----> NH₄+