Sulfur reacts with oxygen to form sulfur dioxide (SO2). This is a combustion reaction that releases heat and light.

Here's the balanced chemical equation:

S(s) + O2(g) → SO2(g)

Explanation:

* S(s): Solid sulfur (sulfur exists as a solid at room temperature)

* O2(g): Oxygen gas (oxygen exists as a diatomic molecule in the air)

* SO2(g): Sulfur dioxide gas (a colorless gas with a pungent odor)

This reaction is highly exothermic, meaning it releases a significant amount of heat. You can observe this reaction by burning sulfur in air, which produces a bright blue flame.

Sulfur dioxide is a major air pollutant and contributes to acid rain. It also has industrial applications in the production of sulfuric acid.