Question 11.2: Drawing Expanded and Condensed Structural Formulas for Alkan...

A molecule of pentane, C_{5}H_{12}, has five carbon atoms in a continuous chain. In the expanded structural formula, the five carbon atoms are connected to each other and to hydrogen atoms by single bonds to give each carbon atom a total of four bonds. In the condensed structural formula, the carbon atoms and their hydrogen atoms on the ends of the chain are written as —CH_{3} and the carbon and hydrogen atoms in the middle are written as —CH_{2}—. The skeletal formula shows the carbon skeleton as a zigzag line where the ends and corners represent C atoms.