1) the symbols for the elements in the compound. 2) the oxidation numbers of the elements involved and write them as superscripts to the right of the elemental symbols. 3) the correct combination of ions to produce a compound with a net charge of zero. (Multiple ions are indicated with subscripts.) 1. Lithium oxide 2. Potassium Chloride 3. Calcium Oxide 4. Barium Bromide