Which of the following ions contains a sulfur atom and has a charge of 1-?

The correct choice is HSO4⁻, which stands for the hydrogen sulfate ion. This ion contains a sulfur atom, as it is derived from sulfuric acid (H₂SO₄) but has lost one hydrogen ion, resulting in a charge of -1. The structure of HSO4⁻ includes one sulfur atom bonded to four oxygen atoms, with one of those oxygens also bonded to a hydrogen atom.

The other options do not meet the criteria of containing both a sulfur atom and a charge of -1. The cyanide ion (CN⁻) does not contain sulfur at all; it is composed of carbon and nitrogen. The bisulfite ion (HSO3⁻) does include sulfur, but its charge is -1, and the sulfate ion also represents sulfur but with a different structure and higher oxidation state compared to the bisulfite ion. The peroxide ion (O2²⁻), on the other hand, consists solely of oxygen atoms and thus does not include sulfur.

Thus, HSO4⁻ is the only ion that satisfies the conditions presented in the question.