1. Formulas

2. Ions Cation: A positive ion Mg2+, NH4+ Anion: A negative ion
Cl-, SO42-
Ionic Bonding: Force of attraction between oppositely charged ions.

3. Predicting Ionic Charges
Group (IA) 1:
Lose 1 electron to form 1+ ions H+
Li+
Na+ K+

4. Predicting Ionic Charges
Group (IIA) 2:
Loses 2 electrons to form 2+ ions
Be2+
Mg2+
Ca2+
Sr2+
Ba2+

5. Predicting Ionic Charges
Group (IIIA) 13:
B3+
Al3+
Ga3+
Loses 3 electrons to form 3+ ions

6. Predicting Ionic Charges
Group (IVA) 14:
Many Group IVA (14) elements rarely form ions.
Lose 4
electrons or gain
4 electrons?

7. Predicting Ionic Charges
Nitride
Group (VA) 15:
Gains 3 electrons to form 3- ions
P3-
Phosphide
As3-
Arsenide

8. Predicting Ionic Charges
Oxide
Group (VIA) 16:
S2-
Sulfide
Gains 2 electrons to form 2- ions
Se2-
Selenide

9. Predicting Ionic Charges
F1-
Fluoride
Br1-
Bromide
Group (VIIA) 17:
Gains 1 electron to form 1- ions
Cl1-
Chloride
I1-
Iodide

10. Predicting Ionic Charges
Group (VIIIA) 18:
Stable Noble gases do not form ions!

11. Predicting Ionic Charges
Groups :
Many transition elements
have more than one possible oxidation state. Roman numerals are used to indicate the oxidation state
Iron(II) = Fe2+
Iron(III) = Fe3+

12. Predicting Ionic Charges
Some transition elements
have only one possible oxidation state.
Groups :
Zinc = Zn2+
Silver = Ag+

13. Writing Ionic Compound Formulas
Example: Iron(III) with chloride
1. Write the formulas for the cation and anion, including CHARGES!
2. Check to see if charges are balanced.
Fe3+
Cl-
3. Balance charges , if necessary, using subscripts. Use parentheses if you need more than one of a polyatomic ion.
Not balanced!
Fe3+
Cl-
4. Name the ions 3
Balanced!
Iron(III) chloride

14. Ba2+ NO3- ( ) Ba2+ NO3- 2 Example: Barium with nitrate Barium nitrate
1. Write the formulas for the cation and anion, including CHARGES!
2. Check to see if charges are balanced.
Ba2+
NO3-
3. Balance charges , if necessary, using subscripts. Use parentheses if you need more than one of a polyatomic ion.
Not balanced!
( )
Ba2+
NO3-
4. Name the ions 2
Barium nitrate
Balanced!

15. NH4+ SO42- ( ) NH4+ SO42- Your Turn! 2 Example: Ammonium with sulfate
1. Write the formulas for the cation and anion, including CHARGES!
NH4+
SO42-
2. Check to see if charges are balanced.
3. Balance charges , if necessary, using subscripts. Use parentheses if you need more than one of a polyatomic ion.
Not balanced!
( )
NH4+
SO42-
4. Name the ions 2
Ammonium sulfate

16. Al3+ S2- S2- Al3+ 3 2 Example: Aluminum with sulfide Aluminum sulfide
1. Write the formulas for the cation and anion, including CHARGES!
2. Check to see if charges are balanced.
Al3+
S2-
3. Balance charges , if necessary, using subscripts. Use parentheses if you need more than one of a polyatomic ion.
Not balanced!
4. Name the ions
S2-
Al3+ 3 2
Aluminum sulfide

17. Mg2+ CO32- Example: Magnesium with carbonate Magnesium carbonate
1. Write the formulas for the cation and anion, including CHARGES!
Mg2+
CO32-
2. Check to see if charges are balanced.
4. Name the ions
They are balanced!
Magnesium carbonate

18. Zn2+ OH- ( ) Zn2+ OH- 2 Example: Zinc with hydroxide Zinc hydroxide
1. Write the formulas for the cation and anion, including CHARGES!
2. Check to see if charges are balanced.
Zn2+
OH-
3. Balance charges , if necessary, using subscripts. Use parentheses if you need more than one of a polyatomic ion.
Not balanced!
( )
4. Name the ions
Zn2+
OH- 2
Zinc hydroxide

19. Ca2+ PO43- ( ) Ca2+ PO43- 3 2 Example: Calcium with phosphate
1. Write the formulas for the cation and anion, including CHARGES!
2. Check to see if charges are balanced.
Ca2+
PO43-
3. Balance charges , if necessary, using subscripts. Use parentheses if you need more than one of a polyatomic ion.
Not balanced!
4. Name the ions
( )
Ca2+
PO43-
Calcium phosphate 3 2