Sulfur (S) is a chemical element with atomic number 16. There are several stable sulfur isotopes but he most common one is ³²P, with 16 protons and 16 neutrons.

Sulfur is the fifth most abundant element by mass on Earth. Being commonly found in nature, it has been known since ancient times across various cultures.

Sulfur is the main building block of sulfuric acid (H₂SO₄), which is in turn used for the extraction or production of many other chemical compounds.