5. COMBINE magnesium and nitrogen Mg +2 N -3 Mg 3 N 2 magnesium nitride Flip flop the charges and turn them into subscripts.
6. K +1 SO 4 -2 Remember, in a Polyatomic ion all the atoms act as one! Even the subscripts!!! If they are already there, they stay there! K 2 SO 4 potassium sulfate potassium and sulfate
7. aluminum and sulfate Al +3 SO 4 -2 Al 2 SO 4 3 ( ) aluminum sulfate How do we separate the subscripts so they look separate?
8. Sample problems 1. Ammonium and chlorine 2. Aluminum and selenate 3. Lead II and bicarbonate 4. Mercury I and phosphate
9. answers 1. NH 4 Cl Ammonium chloride 2. Al 2 (SeO 4 ) 3 Aluminum selenate 3. Pb(HCO 3 ) 2 Lead II bicarbonate 4. (Hg 2 ) 3 (PO 4 ) 2 Mercury I phosphate