- Zn,ZnO,Zn(OH)2Zn , ZnO , Zn ( OH )_{2}
- Cu,BaSO4,CuCl2Cu , BaSO _{4}, CuCl _{2}.
- Na2O,NaOH,Na2CO3Na _{2} O , NaOH , Na _{2} CO _{3}
- MgO,MgCO3,Mg(OH)2MgO , MgCO _{3}, Mg ( OH )_{2}.