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

The charge on Cr must be 3+ for the compound to be charge-neutral with three $S^{2-}$ anions. The name for $Cr_{2}S_{3}$ is the name of the cation, chromium, followed by the charge of the cation in parentheses (III) and the base name of the anion, sulf, with the ending - ide. The full name is chromium(III) sulfide.