Alkane
A hydrocarbon containing only carbon-carbon single bonds and C-H bonds.
Alkene
A hydrocarbon containing one or more carbon-carbon double bonds.
Alkyne
A hydrocarbon containing one or more carbon-carbon triple bonds.
Aromatic hydrocarbon
A six-membered ring written as alternating double and single bonds, although the double bond electrons are actually distributed evenly over all six carbon atoms in the ring.
Benzene
The simplest aromatic hydrocarbon, C(sub 6)H(sub 6).
Branched-chain isomer
A hydrocarbon in which there are one or more carbon atoms bonded to more than two carbons, creating branches in the chain.
Cis
An alkene geometric isomer in which the two large groups on the carbon-carbon double bond are on the same side of the double bond.
Condensed structure
A shorthand notation for writing the chemical structure of a molecule such that each carbon atom and its attached hydrogen atoms are written as a group: C, CH, CH(sub 2), or CH(sub 3). Bonds are omitted except at branch points.
Conformations
Different rotational forms of the same molecule resulting from free rotation about carbon-carbon double and single bonds.
Conjugated
Two or more alternating carbon-carbon double and single bonds.
Cycloalkane
An alkane whose chain of carbon atoms forms a ring structure.
Diene
An alkene with two carbon-carbon double bonds.
Geometric isomers
Compounds with the same chemical formula and the same connectivity of atoms but a different spatial orientation as a result of the restricted rotation about a double bond.
Heteroatom
An atom in an organic molecule that is not carbon or hydrogen.
Hydrocarbon
An organic compound composed of exclusively carbon and hydrogen atoms.
Inorganic compound
A compound that does not contain carbon.
Organic chemistry
The branch of chemistry devoted to the study of carbon-containing compounds and their chemical reactions.
Organic compound
A compound containing carbon atoms.
Pharmaceutical
A drug used for therapeutic purposes. Most are organic compounds.
Polyene
A molecule with more than two carbon-carbon double bonds.
Saturated hydrocarbon
A hydrocarbon with only carbon-carbon dingle bonds and C-H bonds that fits the formula C(sub n)H(sub 2n+2). Does not include cycloalkanes.
Skeletal line structure
A shorthand notation for writing chemical structures in which carbon and hydrogen atom symbols are not written as lines in a zigzag format.
Straight-chain isomer
A hydrocarbon in which every carbon atom is bonded to at most two other carbon atoms, creating a straight chain without branches.
Structural isomers
Compounds that have the same chemical formula but differ in the connectivity of the atoms. Structural isomers are different compounds that exhibit different physical and chemical properties and have different IUPAC names.
Substuituant
A carbon branch along the main chain where a hydrogen atom has been substituted with a chain of one or more carbons.
Trans
An alkene geometric isomer in which the two large groups on the carbon-carbon double bond are on the opposite side of the double bond.
Unsaturated hydrocarbon
A compound containing one or more carbon-carbon double or triple bonds, or a cycloalkane or an aromatic hydrocarbon. It has fewer than 2(sub n)+2 hydrogens, where n is the number of carbon atoms.