CoachA molecule can be written in four ways:
- its molecular formula gives only the number of atoms of each element, such as ;
- its structural formula shows every atom and every bond;
- its semi-structural formula shows the bonds between carbon atoms and groups the hydrogen atoms with their carbon, such as ;
- its skeletal formula draws only the bonds of the carbon skeleton as a zigzag: each end and each corner is a carbon atom, the hydrogen atoms on carbon are not drawn, and every other atom (with its hydrogen atoms) is written.
Examples
Example 32.3 (Reading a skeletal formula)
In the skeletal formula of butane, the zigzag has two ends and two corners: four carbon atoms. Each end carbon has one bond drawn, so it carries three hydrogen atoms (); each corner has two bonds drawn, so it carries two (). Every carbon has four bonds in all, which gives back .