1. Polyatomic Ions
= Group of atoms that behaves like a unit, and has a charge.
CO32-
charge -2
1 atom
3 atoms

2. Polyatomic Ions
How do they form?

3. CO32-
carbonate

4. NH4+
ammonium

5. SO42-
sulfate

6. SO32-
sulfite

7. PO43-
phosphate 5

8. PO33-
phosphite

9. NO3-
nitrate

10. NO2-
nitrite

11. ClO3-
chlorate 10

12. ClO2-
chlorite

13. ClO4-
perchlorate

14. ClO-
hypochlorite

15. ClO4- perchlorate ClO3- chlorate ClO2- chlorite ClO- hypochlorite
Summarizing the chlorates:
ClO4-
perchlorate
ClO3-
chlorate
ClO2-
chlorite
ClO-
hypochlorite

16. OH-
hydroxide 15

17. CN-
cyanide

18. CH3COO- or C2H3O2-
acetate

19. HSO4-
Hydrogen sulfate

20. HSO3-
Hydrogen sulfite

21. MnO4-
permanganate 20

22. Hydrogen carbonate (“bicarbonate”)
HCO3-
Hydrogen carbonate (“bicarbonate”)

23. CrO42-
Chromate

24. Cr2O72-
Dichromate

25. C2O42-
oxalate

26. H3O+
hydronium 25

27. BrO3-
bromate 25

28. CO32-
carbonate

29. HPO42-
Hydrogen Phosphate

30. Di-hydrogen Phosphate
H2PO4-
Di-hydrogen Phosphate

31. O22-
peroxide

32. IO3-
Iodate 30

33. C4H4O62-
Tartrate

34. S2O32-
Thiosulfate

35. BO33-
Borate

36. BrO4-
Perbromate 35

37. BrO-
Hypobromite

38. SCN-
Thiocyanate

39. Other Ions

40. Sn4+
Tin IV (stannic)

41. Sn2+
Tin II (stannous)

42. Cu2+
Copper II
(Cupric)

43. Cu+
Copper I
(Cuprous)

44. Fe3+
Iron (III)
(Ferric)

45. Fe2+
Iron (II)
(Ferrous) 40