The term "alkyl" refers to a functional group (or substituent) that is derived from the alkanes by the removal of a hydrogen atom. The name of the particular alkyl group is taken from the stem name of the alkane, with the -ane being replaced with -yl. For example, the derived alkyl group from methane is the methyl group. Methane has the chemical formula CH₄ and the methyl group is CH₃. The first four alkyl groups are methyl, ethyl, propyl, and butyl, with the number of carbon atoms being one, two, three, and four respectively. Isomers are possible with an alkyl just as with the alkane parent, so, for example, isopropyl exists as well as propyl. The isopropyl group [(H₃C)₂HC-] has a different point (carbon atom) of attachment than the propyl group (H₃CH₂CH₂C-). The symbol often used to denote an alkyl group...