The ions charge comes from the number of valence electrons. All elements excluding transition metals want to have 8 valence electrons. The first 3 groups will try to lose electrons to get to 8 where as the 5, 6, and 7 ones will try to gain electrons. Hydrogen is to small to get 8 electrons so it settles for 2 like helium because helium is a noble gas. oxygen needs 2 electrons and hydrogen gives one thats hy H is positive H3O is positive and OH is nwgitive.
