2. FLUOR F-1FLUOR F-1 CLORO Cl-1 +1 +3 +5 +7CLORO Cl-1 +1 +3 +5 +7 BROMO Br -1 +1 +3 +5 +7BROMO Br -1 +1 +3 +5 +7 YODO I-1 +1 +3 +5 +7YODO I-1 +1 +3 +5 +7

3. OXIGENO O -2 AZUFRE S-2 +2 +4 +6 SELENIO Se-2 +2 +4 +6 TELURO Te-2 +2 +4 +6

4. NITROGENO N -3 FOSFORO P -3 +3 +5 ARSENICO As -3 +3 +5 ANTIMONIO Sb -3 +3 +5

5. BORO B-3 +3 CARBONO C-4 +4 SILICIO Si -4 +4

6. LITIOLi+1 SODIO Na+1 POTASIOK+1 AMONIONH4+1 PLATA Ag+1

7. MAGNESIO Mg+2 CALCIOCa+2 ESTRONCIOSr+2 BARIO Ba+2 RADIO Ra+2 ZINCZn+2

8. ALUMINIO Al+3 BISMUTO Bi+3 COBRE Cu+1+2 MERCURIO Hg+1+2 CADMIO Cd+1+2 ALUMINIO Al+3 BISMUTO Bi+3 COBRE Cu+1+2 MERCURIO Hg+1+2 CADMIO Cd+1+2

9. OROAu+1+3 FIERROFe+2+3 NIQUELNi+2+3 COBALTOCo+2+3 CROMOCr+2+3 MAGNESIO Mg+2+3

10. PLOMOPb+2+4 PLATINOPt+2+4 ESTAÑOSn+2+4 BISMUTOBi+5 CROMOCr+6 MANGANESOMn+4+6+7