Carbon
Uploaded by Admin on Jan 22, 1999
I. Introduction
A. The History of Carbon
II. Occurrences in Nature
A. Diamond
B. Graphite
C. Coal and Charcoal
D. Amorphous Carbon
III. Carbon Compounds
A. Inorganic
B. Organic
IV. The Carbon Cycle
V. Conclusion
Carbon, an element discovered before history itself, is one of the most abundant elements in the universe. It can be found in the sun, the stars, comets, and the atmospheres of most planets. There are close to ten million known carbon compounds, many thousands of which are vital to the basis of life itself (WWW 1).
Carbon occurs in many forms in nature. One of its purest forms is diamond. Diamond is the hardest substance known on earth. Although diamonds found in nature are colorless and transparent, when combined with other elements its color can range from pastels to black. Diamond is a poor conductor of heat and electricity. Until 1955 the only sources of diamond were found in deposits of volcanic origin. Since then scientists have found ways to make diamond from graphite and other synthetic materials. Diamonds of true gem quality are not made in this way (Beggott 3-4).
Graphite is another form of carbon. It occurs as a mineral in nature, but it can be made artificially from amorphous carbon. One of the main uses for graphite is for its lubricating qualities. Another is for the "lead" in pencils. Graphite is used as a heat resistant material and an electricity conductor. It is also used in nuclear reactors as a lubricator (Kinoshita 119-127).
Amorphous carbon is a deep black powder that occurs in nature as a component of coal. It may be obtained artificially from almost any organic substance by heating the substance to very high temperatures without air. Using this method, coke is produced from coal, and charcoal is produced from wood. Amorphous carbon is the most reactive form of carbon. Because amorphous carbon burns easily in air, it is used as a combustion fuel. The most important uses for amorphous carbon are as a filler for rubber and as a black pigment in paint (WWW 2).
There are two kinds of carbon compounds. The first is inorganic. Inorganic compounds are binary compounds of carbon with metals or metal carbides. They have properties ranging from reactive and saltlike; found in metals such as sodium, magnesium, and aluminum, to an unreactive and metallic, such as titanium and niobium (Beggott 4).
Carbon compounds containing nonmetals are usually gases or liquids with low boiling...