## Chemistry: Molecular Approach (4th Edition)

a) NaF is made of $Na^+$ and $F^-$. b) CaO is made of $Ca^{2+}$ and $O^{2-}$. c) $SrBr_2$ is made of $Sr^{2+}$ and 2 $Br^-$. d) $K_2O$ is made of 2 $K^{+}$ and $O^{2-}$. The cations have no valence electrons, and the anions have full octets.