I know that it is possible for 2 H2O molecules to gain and lose electrons. This reaction looks like this: 2 H2O -> H2O+ + H2O- This causes 1 of the oxygen atoms to be hypervalent since it now has 9 electrons. The other oxygen has only 7 electrons. The electron on the hypervalent oxygen came from 1 of the other oxygen's lone pairs. Obviously this ionic water is not stable. But how is this ionic water possible when it violates 1 of the general rules in chemistry which is that hypervalency starts in the 3rd period not group 16 of the 2nd period.