Cyclohexane. Computer illustration of a molecule of cyclohexane (formula: C6H12) in its chair conf- ormation. Atoms are represented as cylinders and are colour-coded: carbon (yellow) and hydrogen (white). This compound is not fixed in this shape, but may alter to assume other conformations, as the carbon-carbon bonds can rotate freely. The chair form has one carbon atom above and one below the plane of the other four. 99% of cyclohexane molecules exist in this form under normal condit- ions, as all the carbon atoms are as far away from each other as possible, reducing unfavourable int- eractions. See image A705/050 for the boat form.