Composition and Structure of the Water Molecule
Characteristics and properties of waters - Pure water, natural waters

A water molecule can decompose into gaseous components or dissociate into ions, which is why it has various scientific names:

• by thermolysis (partially achieved by Lavoisier in 1785, as noted above, at a temperature of about 750 °C; it is believed to be complete only at around 3,000 °C) or by electrolysis (first performed by Volta in 1800), hydrogen and oxygen are produced, which shows that water is a hydrogen (or dihydrogen) oxide or an oxygen acid (it is also sometimes said that water is an “oxygen hydride,” which is actually a misnomer because this term does not meet the definition of a hydride, in which the H atom is electronegative);

• Through autoprotolysis, it partially dissociates: