A given alkane can be drawn arbitrarily in many ways. For example, the straight-chain, Four-carbon alkane called butane can be represented by any of the structures shown in Figure 3.2. These structures don’t imply any particular three-dimensional geometry for butane; they indicate only the connections among atoms. In practice, as noted in Section 1.12, chemists rarely draw all the bouds in a molecule and usually refer to butane by the condensed structure,〖CH〗_3 〖CH〗_2 〖CH〗_2 〖CH〗_3 or 〖CH〗_3 (〖CH〗_2 )_2 〖CH〗_3 Still more simply, butane can even be represented as n-C_4 H_10 , where n denotes normal (straight-chain) butane.