The longest series of linked carbon atoms in a molecule is known as its carbon skeleton or carbon backbone. The number of carbon atoms may be thought of as the size of the alkane. With their repeated -CH2- units, the alkanes constitute equilibrator weizmann forex homologous series of organic compounds in which the members differ in molecular mass by multiples of 14. Alkanes are not very reactive and have little biological activity.
An alkyl group, generally abbreviated with the symbol R, is a functional group that, like an alkane, consists solely of single-bonded carbon and hydrogen atoms connected acyclically—for example, a methyl or ethyl group. Saturated hydrocarbons are hydrocarbons having only single covalent bonds between their carbons. According to the definition by IUPAC, the former two are alkanes, whereas the third group is called cycloalkanes. C4H4 alkane and so has no alkane isomer. Alkanes with more than three carbon atoms can be arranged in various different ways, forming structural isomers.