1. Ionic Charges Group 1A +1 Group 2A +2 Group 3A +3
Monatomic ions formed as follows:
Group 1A +1
Group 2A +2
Group 3A +3
Al is only common Group 3A metal

2. Groups 1A- 3A form cations- Ionic charge is positive and equal to the group number
Group A nonmetals form anions- ionic charge is negative and equal to 8 – group number

4. Group A Nonmetals Group 7A -1 Group 6A -2 Group 5A -3
Group 4A and O usually do NOT form ions

7. Group O rarely form compounds
Nonmetals in Group 4A - C and Si form molecular compounds

8. Transition Metals Have more than one ionic charge
Also true of metals in Group 4A- Pb and Sn

9. Naming Transition Ions
Stock System- name of element (roman numeral-charge)
Sn+4 Tin (IV) ion

10. Naming Transition Ions
Classical System-
-ous for lower ionic charge
-ic for higher ionic charge
Sn+4 Stannic ion

11. Classical Name Related to Symbol
Fe - ferrous / ic
Pb - plumbous / ic
Sn - stannous / ic
Disadvantage- do not know the charge of the ion

13. Transition Metals with only one ionic charge
Ag +
Cd +2
Zn +2

14. Practice Write the symbol & charge for the ion of each atom:
Barium
Selenium
Chromium 3 e- lost
Neon
Iodine
Iron 2 e- lost
Ba+2
Se-2
Cr+3
No ion formed
I –
Fe +2

15. Polyatomic Ions Composed of more than one atom
Tightly bonded and function as a unit and carry a charge
Nitrate NO3-
1 Nitrogen and 3 Oxygen
Most end in –ate or -ite

17. Exceptions
NH4+ ammonium
CN- cyanide
OH- hydroxide

18. -ite/ -ate pairs So3-2 sulfite SO4-2 sulfate NO2- nitrite NO3- nitrate
ClO2- chlorite ClO3- chlorate
-ite ending has 1 less Oxygen than -ate (charges are same)

19. Polyatomic H ions Begins with H Think of it as H+ + another polyatomic
Hydrogen carbonate
H+ + CO HCO3-
Sum of charges

20. Hydrogen phosphate
H+ + PO HPO4-2
Dihydrogen phosphate
H+ + HPO H2PO4-

21. HCO3- , HPO4-2 , H2PO4-
Essential for life
CN- (Cyanide) poison- blocks energy production
ClO- (Hypochlorite) bleach

22. Naming Ionic Compounds
Section 9.2

23. Antoine-Laurent Lavoisier
French Chemist
Developed systematic method for naming chemical compounds

24. Binary Ionic Compounds
Place Cation name first, followed by Anion name
Cs2O Cesium oxide
SrF Strontium fluoride

25. Additional Naming CuO Not Copper oxide Cu+ or Cu2+ Therefore:
Copper (II) oxide or
Cupric oxide
Try SnF2 and SnS2

26. SnS2 SnF2 Sn2+ or Sn4+ Ratio 1:2 F-1 So Sn2+ Sn2+ or Sn4+ Ratio 1:2
Tin (II) fluoride or
Stannous fluoride
Sn2+ or Sn4+
Ratio 1:2
S-2
So Sn+4
Tin (IV) sulfide or
Stannic sulfide

27. Writing Formulas Write the symbol of the cation and then the anion.
Add subscripts needed to balance the charges.

28. Fe+3 + O-2 Crisscross charges Fe2O3
Iron (III) oxide
Fe O-2
Crisscross charges
Fe2O3

29. Ca+2 + S-2 Ca2S2 But want lowest whole number ratio, so: CaS
Calcium sulfide
Ca S-2
Ca2S2 But want lowest whole number ratio, so:
CaS

30. Compounds with Polyatomic Ions
Write the symbol for the cation followed by the formula for the polyatomic ion, and then balance the charges.
Calcium nitrate
Ca (NO3)-1
Crisscross charges for subscripts
Ca1(NO3)2 so: Ca(NO3)2