Facts About Sulfur

Credit: Greg Robson/Creative Commons, Andrei Marincas | Shutterstock
Atomic Number: 16
Atomic Symbol: S
Atomic Weight: 32.065
Melting Point: 247.3 F (119.6 C)
Boiling Point: 832.3 F (444.6 C)

Word origin: From the Sanskrit sulvere and the Latin sulphur, meaning "to burn."

History: Humans have known about sulfur since ancient times. In the Bible, it is referred to as brimstone.

Properties of sulfur

Sulfur is a pale yellow, odorless, brittle solid. It is classified as a nonmetal in Group 15, the pnictogens, or nitrogen family. [See Periodic Table of the Elements]

It is insoluble in water but soluble in carbon disulfide. Whether as a gas, liquid, or solid, elemental sulfur has more than one allotropic form or modification, resulting in a multitude of sulfur forms whose relations are not fully understood.

There are many compounds of sulfur that are important to scientists. Some are calcium sulfur, ammonium sulfate, carbon disulfide, sulfur dioxide and hydrogen sulfide. Precaution must be taken when handling carbon disulfide, hydrogen sulfide, and sulfur dioxide.

Sulfur dioxide is a dangerous component in atmospheric air pollution. Sulfur hexafluoride, a greenhouse gas, is six times denser than air. Inhaling it — which is dangerous — lowers the timbre of a person's voice. Sulfur trioxide is the primary agent in acid rain.

In high concentrations, exposure to hydrogen sulfide can quickly lead to death by respiratory paralysis. In small concentrations it can be metabolized, however. Hydrogen sulfide is insidious because it deadens the sense of smell, meaning that those exposed do not realize their risk.

There are eleven isotopes of sulfur. Four of them are found in nature and those are not radioactive.

Sources of sulfur

Sulfur occurs in nature around volcanoes and hot springs. It is also found in meteorites. Additionally, sulfur is found as iron pyrites, galena, sphalerite, cinnabar, stibnite, gypsum, Epsom salts, celestite, barite and more.

Volcanic sulfur
Volcanic sulfur
Credit: Kletr | Shutterstock

For commercial purposes, humans extract sulfur from wells sunk into salt domes along the Gulf Coast of the United States. Heated water is forced into the wells to melt the sulfur, which is then brought to the surface.

Sulfur occurs in natural gas and petroleum crudes and must be removed from them in order for these products to be used. Historically, the removal process has been done chemically, which destroyed the sulfur. Newer processes allow the sulfur to be recovered for human use.

Uses of sulfur

Sulfur is essential to life. It is a minor component of fats, bodily fluids and skeletal minerals.

Sulfur is a component of black gunpowder. It is also a good insulator.

Sulfur's many uses include:

  • Vulcanization of natural rubber
  • As a fumigant and a fungicide
  • Making phosphatic fertilizers. It is used extensively for this purpose.
  • Producing sulfuric acid, one of the most important manufactured chemicals. The process requires a tremendous amount of sulfur.
  • Making sulfite paper and other papers
  • Bleaching dried fruits

(Source: Los Alamos National Laboratory)

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