1. Review of Elements and Symbols

2. P Phosphorous Ag Silver Cu Copper N Nitrogen

3. Na Sodium Hg Mercury I Iodine O Oxygen

4. K Potassium H Hydrogen CI Chlorine F Fluorine

5. He Helium Zn Zinc Li Lithium Br Bromine

6. B Boron Ca Calcium C Carbon Mg Magnesium

7. Pb Lead Sn Tin S Sulfur Ni Nickel

8. Si Silicon Be Beryllium Ar Argon Ne Neon

9. Al Aluminum Cr Chromium Co Cobalt Ba Barium Fe Iron

10. AluminumAl Copper Cu Boron B Carbon C Lithium Li

11. Iron Fe SulfurS Sodium Na Phosphorus P Cobalt Co

12. BariumBa SilverAg ZincZn Argon Ar Nitrogen N

13. OxygenO Mercury Hg Beryllium Be Iodine I Chlorine Cl

14. HydrogenH Silicon Si CalciumCa Neon Ne Potassium K

15. LeadPb Tin Sn Magnesium Mg Bromine Br NickelNi

16. FluorineF Helium He Chromium Cr Bromine Br

17. Mercury Hg

18. PbLead

19. AgSilver

20. SnTin

21. PotassiumK

22. IronFe