| A | B |
|---|
| hydrocarbons | organic compounds that contain only carbon and hydrogen |
| alkanes | hydrocarbons that contain only single covalent bonds |
| straight-chain alkanes | alkanes that contain any number of carbons one after another in a chain |
| substituent | atom or group of atoms that take the place of a hydrogen atom in a hydrocarbon molecule |
| alkyl group | a hydrocarbon substituent |
| branched-chain alkanes | alkanes that contain one or more alkyl substituents |
| unsaturated compounds | organic compounds that contain double or triple carbon-carbon bond |
| saturated compounds | hydrocarbons that contain the maximum number of hydrogen atoms per carbon atom |
| alkenes | contain at least one carbon-carbon double bond |
| alkynes | contain at least one carbon-carbon triple bond |
| isomers | compounds that have the same molecular formula but different molecular structures |
| structural isomers | molecules in which the atoms are joined in the same order, but the arrangements of the atoms in space are different |
| stereoisomers | compounds that have the same molecular formula, but the atoms are joined in a different order |
| geometric isomers | isomers that differ in the concentration of groups around a double bond |
| trans configuration | configuration with substituted groups on opposite sides of the double bond |
| cis configuration | configuration with substituted groups on the same side of the double bond |
| asymmetric carbon | a carbon with four different groups attached |
| optical isomers | pairs of molecules that differ only in the way four different groups are arranged around a central carbon atom |
| cyclic hydrocarbons | organic compounds that contain hydrocarbon rings |
| resonance | when two or more equally valid structures can be drawn for a molecule |
| phenyl group | name given to a benzene ring when it is a substituent |
| aromatic compounds | group of hydrocarbons that contain a benzene ring or a ring with bonding like that of benzene |
| cracking | process by which hydrocarbons are broken down into smaller molecules |
| petroleum | fossil fuel containing straight- and branched-chain alkanes |
| distillation | process by which petroleum is separated into fractions |
| lignite | brown coal, consisting of about 50 percent carbon |
| anthracite | hard coal, which is high in carbon content |
