Bronsted-lowery Acids and Bases
in 1923 the Danish chemist Johannes Bronsted(1879-1947), and the english chemist Thomas Lowry (1874-1936)
proposed a more general definition of acids and bases, their concept is based on the fact that acid-base reactions involve the transfer of H+ ions from one substance to another.
The H+ ion in water
HCl is ionized in water to form H+(aq)
an H+ ion is a proton with no surrounding valence electron.
this small, positively charged particle interacts strongly with the nonbonding electron pairs of water molecule to form hydrated hydrogen ions.
example, the interaction of a proton with one water molecule forms hydronium ion H3O+.