notam hidroxidul metalului M(OH)2
miu.M(OH)2 = Am+34 g/mol, Am = masa atomica a lui M
100% hidroxid ........................... 80,12% M
Am+34 g .................................... Am
=> Am = 137 u.a.m. => M = Ba
=> hidroxidul = Ba(OH)2
BaO + H2O --> Ba(OH)2