1. Net Ionic Equations

2. Writing a Complete Ionic Equation
Start with a balanced molecular equation.
Break all soluble strong electrolytes (compounds with (aq) beside them) into their ions
indicate the correct formula and charge of each ion
indicate the correct number of each ion
write (aq) after each ion
Bring down all compounds with (s), (l), or (g) unchanged

3. 2 Na3PO4 (aq) + 3 CaCl2 (aq) --> 6 NaCl (aq) + Ca3(PO4)2 (s)
6 Na+ (aq) + 2 PO43- (aq) + 3 Ca2+ (aq) + 6 Cl- (aq) --> 6 Na+ (aq) + 6 Cl- (aq) + Ca3(PO4)2 (s)

4. Spectator Ions
Spectator ions -are present in the reaction mixture but do not participate in it.
. You can recognize spectator ions by looking for ions that are present on both sides of the equation.

5. Writing a net ionic equation
Take your complete ionic equation and:
Cross out the spectator ions that are present.
Write the "leftovers" as the net ionic equation.
6 Na+ (aq) + 2 PO43- (aq) + 3 Ca2+ (aq) + 6 Cl- (aq) --> 6 Na+ (aq) + 6 Cl- (aq) + Ca3(PO4)2 (s)
2 PO43- (aq) + 3 Ca2+ (aq) --> Ca3(PO4)2 (s)

6. 3 (NH4)2CO3 (aq) + 2 Al(NO3)3 (aq) --> 6 NH4NO3 (aq) + Al2(CO3)3 (s)
2 NaOH (aq) + H2SO4 (aq) --> Na2SO4 (aq) + 2 H2O (l)
Mg (s) + 2 HCl (aq) --> MgCl2 (aq) + H2 (g)
Zn (s) + CuSO4 (aq) --> ZnSO4 (aq) + Cu (s)
Na2CO3 (aq) + 2 HNO3 (aq) --> 2 NaNO3 (aq) + H2O (l) + CO2 (g)