Elements
Organic Compounds
Organic chemistry is the chemistry of carbon, an element that forms strong chemical bonds to other carbon atoms as well as to many other elements like hydrogen, oxygen, nitrogen and the halogens. Because of it versatility in forming covalent bonds, there are well over a million known carbon compounds. Many are composed of only carbon and hydrogen, collectively called hydrocarbons. Most hydrocarbons are obtained from petroleum. Carbon always forms four covalent bonds (4 shared pairs of electrons) that may be present as 4 single bonds per atom, or 2 single bonds and 1 double bond, or 1 single bond and 1 triple bond. With the ability of carbon to bond in different ways, an important part of organic chemistry concerns the structure of compounds. For example, three organic compounds have the identical molecular formula, C5H12, but they are different because each connects the 5 carbon atoms together in a different arrangement. Compounds with the same formula but different structures are called isomers. In organic chemistry, both structure and composition are of prime importance.
Organic chemistry is important because the vital biological molecules in living systems are largely organic compounds. Nearly all commonly used plastics are prepared from organic compounds.
