CHEM 121 glossary
Skeletal (line-bond) structure
A shorthand drawing of an organic molecule in which lines are bonds and every vertex or unlabelled line end is a carbon atom. Hydrogens on carbon are not drawn (each C carries enough to make four bonds), but heteroatoms and any H atoms on them are always written.
Example
A zig-zag of five lines is hexane, : the 2 line ends are and the 4 vertices are , so H = 3 + 2 + 2 + 2 + 2 + 3 = 14.