Sulfur

Sulfur is a bright yellow, brittle nonmetal that has been known since ancient times, when it was called brimstone. It occurs naturally near volcanoes, but today most of it is recovered as a byproduct of cleaning sulfur out of oil and natural gas.

Most sulfur is turned into sulfuric acid, one of the most produced chemicals in the world. That acid makes fertilizers, helps extract metals from ores, and cleans silicon wafers in chip factories. Sulfur also toughens rubber in a process called vulcanization, goes into gunpowder, and is part of the proteins in every living thing. Many of its compounds, such as rotten-egg-smelling hydrogen sulfide, are famously smelly.