| Atomic Number: | 16 | Atomic Symbol: | S |
| Atomic Weight: | 32.06 | Electron Configuration: | 2-8-6 |
| Shells: | 2,8,6 | Filling Orbital: | 3p4 |
| Melting Point: | 112.8oC | Boiling Point: | 444.6oC |
| Uses: | Fire works, medicines, rubber and pesticides |
History
(Sanskrit, sulvere; L. sulpur) Known to the ancients; referred
to in Genesis as brimstone.
Sources
Sulfur is found in meteorites. R.W. Wood suggests that the dark
area near the crater Aristarchus is a sulfur deposit.
Sulfur occurs native in the vicinity of volcanoes and hot springs. It is
widely distributed in nature as iron pyrites, galena, sphalerite, cinnabar,
stibnite, gypsum, epsom salts, celestite, barite, etc.
Production
Sulfur is commercially recovered from wells sunk into the
salt domes along the Gulf Coast of the U.S. Using the Frasch process heated
water is forced into the wells to melt the sulfur, which is then brought to the
surface.
Sulfur also occurs in natural gas and petroleum crudes and must be removed
from these products. Formerly this was done chemically, which wasted the sulfur;
new processes now permit recovery. Large amounts of sulfur are being recovered
from Alberta gas fields.
Properties
Sulfur is pale yellow, odorless, brittle solid, which is
insoluble in water but soluble in carbon disulfide. In every state, whether gas,
liquid or solid, elemental sulfur occurs in more than one allotropic form or
modification; these present a confusing multitude of forms whose relations are
not yet fully understood.
In 1975, University of Pennsylvania scientists reported synthesis of
polymeric sulfur nitride, which has the properties of a metal, although it
contains no metal atoms. The material has unusual optical and electrical
properties.
Amorphous or "plastic" sulfur is obtained by fast cooling of the crystalline
form. X-ray studies indicate that amorphous sulfur may have a helical structure
with eight atoms per spiral. Crystalline sulfur seems to be made of rings, each
containing eight sulfur atoms, which fit together to give a normal X-ray
pattern.
Isotopes
Eleven isotopes of sulfur exist. None of the four isotopes that
in nature are radioactive. A finely divided form of sulfur, known as flowers of
sulfur, is obtained by sublimation.
Compounds
Organic compounds containing sulfur are very important.
Calcium sulfur, ammonium sulfate, carbon disulfide, sulfur dioxide, and hydrogen
sulfide are but a few of the many important compounds of sulfur.
Uses
Sulfur is a component of black gunpowder, and is used in the
vulcanization of natural rubber and a fungicide. It is also used extensively in
making phosphatic fertilizers. A tremendous tonnage is used to produce sulfuric
acid, the most important manufactured chemical.
It is used to make sulfite paper and other papers, to fumigate fumigant, and
to bleach dried fruits. The element is a good insulator.
Sulfur is essential to life. It is a minor constituent of fats, body fluids,
and skeletal minerals.
Handling
Carbon disulfide, hydrogen sulfide, and sulfur dioxide should
be handled carefully. Hydrogen sulfide in small concentrations can be
metabolized, but in higher concentrations it quickly can cause death by
respiratory paralysis.
It quickly deadens the sense of smell. Sulfur dioxide is a dangerous
component in atmospheric air pollution.
Availability
High-purity sulfur is commercially available in purities of
99.999+%.