Cadmium

Cadmium, symbol, Cd, is a silvery
white metallic chemical element with a faint blue
tinge to it. It is the fifty-seventh most commonly
found element in the earth. It was discovered by
F. Stromeyer, in 1817, in Germany. Stromeyer
was studying a sample of zinc carbonate which
separated into a the new element ultimately called
cadmium. The only cadmium materials,
greenockite (cadmium sulfide) and otavile
(cadmium carbonate) are found in zinc oxide and
zinc carbonate. Cadmium, which is usually
associated with zinc has some differences; some of
which are that cadmium is softer and has a lower
melting and boiling point than zinc. There are five
basic states of cadmium. First, there is the regular
raw metal cadmium. Then there is cadmium oxide
which is formed by burning the raw metal in the air
producing brown smoke. Cadmium oxide can also
be formed by heating cadmium carbonate in acid
or ammonia producing a brown powder. By doing
this, cadmium and oxygen are being mixed.
Cadmium carbonate is made by absorbing carbon
dioxide into the raw metal or mixing cadmium salts
with ammonium carbonate, forming a salt-like
substance. Cadmium sulfide is made by mixing
hydrogen sulfide with a solution of cadmium ions,
resulting in a range of colors from lemon yellow to
a deep red. Cadmium halides are compounds with
complex cadmium ions in them to form varied
structure solutions. The regular structure of a
cadmium atom is that it has four electron shells
with a total of 48 electrons in it. The main use for
cadmium is to plate iron, steel and other metals,
protecting them from corrosion. This method has
been used since 1919. The use of cadmium has to
be limited because it gives off large numbers of
toxins into the environment. The use of cadmium
has gradually decreased in order to help the
environment. It is not used to plate food
processing parts or ovens because of this.
Cadmium may be found in some cereals, nuts and
vegetables, but scientists doubt that, if taken is
small quantities, it would prove harmful. Cadmium
is also used for nickel-cadmium batteries and
nuclear control rods. It is used in compounds, for
example, with copper to harden them. Since the
color of cadmium sulfide varies it is useful for
pigments in ceramics, glass, paints, plastics and
other items. It is also used in compounds as a
stabilizer in thermo- setting plastics. Chemical
Properties symbol Cd atomic number 48 atomic
weight 112.40 melting point 321 C boiling point
765 C I hope that you have learned as much as I
have from this report. CADMIUM 8-K 11/4/92
Bibliography Basford, Leslie , Kogan, Philip. The
Elements And Their Order. London: Sampson
Low, Marston and Co., 1966.
"Cadmium",McGraw-Hill Encyclopedia of
Science and Technology, 1987 edition.
"Cadmium", Van Nostrand\'s Scientific
Encyclopedia, 1989 edition.

Category: Science