What is the charge of the thiocyanate ion?

The thiocyanate ion is represented by the formula SCN⁻. Its charge is negative one, which indicates that the ion has gained an electron. This results from the typical behavior of sulfur and carbon, where the sulfur atom can form a bond with carbon and nitrogen while still exhibiting a net negative charge.

Thiocyanate consists of one sulfur atom covalently bonded to a carbon atom, which in turn is bonded to a nitrogen atom. The nitrogen has a tendency to carry a partial negative charge due to its higher electronegativity compared to sulfur and carbon, contributing to the overall negative charge of the ion.

In contrast, the other options provided represent different species. The SCN²⁻ option would imply that the thiocyanate ion has an unusual charge of negative two, which is incorrect. The SO₄²⁻ represents a sulfate ion, and SO₃²⁻ represents a sulfite ion, neither of which is related to thiocyanate. Therefore, the correct charge of the thiocyanate ion being SCN⁻ aligns with the understanding of its composition and bonding, confirming that the correct answer is indeed SCN⁻.