metals tend to form cations
nonmetals tend to form anions
this is because metals lose electrons,
and nonmetals gain electrons
<span>HofO3 - [H of O(g) + H of O2] = deltaH
HofO3 = -107.2kJ/mol + 249.8 + 0 (Heat of formn.of O2 is 0
= +142.6kJ/mol </span>