3. Formulae and Equations

Binary Compounds

• Contains 2 elements only

• Change the second element’s ending to -ide

Polyatomic Ions

• An ion which contains atoms of more than 1 element bonded together

Common Polyatomic Ions

• NH₄+ (Ammonium)

• OH^-  (Hydroxide)

• CO₃^2-  (Carbonate)

• NO₃  (Nitrate)

• SO₄^2- (Sulfate)

Balancing Equations

• Metals first

• Non-metals

• Carbon

• Hydrogen

• Oxygen

Diatomic Molecules

• An element containing 2 atoms bonded together