# What is the oxidation number of sulfur?

The oxidation number of any element in its elemental state is $0$.
So sulfur is zerovalent, just at oxygen is as the ${O}_{2}$ molecule or in its atomic state. Because sulfur is in $G r o u p$ $V I$, it has very similar redox behaviour to oxygen (or rather because oxygen and sulfur have similar chemistry, we, as chemists, put it in Group VI). Sulfur can have many oxidation states; its maximum number is $V {I}^{+}$, for example in sulfuric acid or in $S {O}_{3}$.