Which of the following is an example of a structural formula for butane?

The structural formula provides a visual representation of how atoms are connected in a molecule. In the case of butane, which has the molecular formula C4H10, the structure consists of a straight chain of four carbon atoms, each bonded to sufficient hydrogen atoms to satisfy their tetravalent nature (each carbon atom forming four bonds).

The choice that illustrates the structural arrangement of butane is represented as CH3CH2CH2CH3. This formula explicitly shows each carbon atom and the connections between them, making it clear that there are four carbon atoms in a linear configuration, which is characteristic of butane. Each "CH3" and "CH2" indicates the specific bonding and the presence of hydrogen atoms.

The other options do not adequately represent the structure of butane. For instance, C3H8 refers to propane, which has only three carbon atoms. CH4 represents methane, with just one carbon atom, and CH3(CH2)3CH3 does depict butane but in a condensed formula format that, while still valid, does not as clearly convey the sequential order of each carbon atom and their hydrogen attachments compared to the other choice. Consequently, the choice illustrating each carbon atom in a linear sequence best represents butane's structure