## Chemistry: A Molecular Approach (3rd Edition)

Calcium Fluoride - CaF$_{2}$
1. To begin, write the formula of the first element with its charge. Ca$^{2+}$ 2. Then write the formula of the second element (fluoride is fluorine) along with its charge. F$^{-}$ 3. Cross down the charges of both of the elements (+2 and -1) to get: $$CaF_{2}$$