This module develops a scheme emphasizing several aspects of the chemistry of sulfur, the second Group 16 element.

Sulfur has six valence electrons (3s² 3p⁴). Some of the important sulfur species are shown below with the oxidation state of sulfur in each.

+6	SO3
+4	SO2
0	S
–2	H2S, S2–

Sulflur exists as S^2– in its binary compounds with metals such as with Na⁺ in Na₂S.