Structural Formula

Even the condensed formulas take up a lot of space and a lot of time to write. They can be transformed still further by the shorthand of line formulas. Line formulas show the main bonds of the molecule instead of the individual atoms, and only show a particular atom if it is different from carbon or hydrogen, or if it is involved in a reaction under consideration. Our examples of condensed formulas look like this when represented by line formulas.

At each unmarked vertex of the lines, there is a carbon atom with enough hydrogen atoms to satisfy its valence of four. There is also a carbon atom with its accompanying hydrogen atoms at the end of any bond line that doesn't show some other atom. Compare the condensed formulas of these three compounds with the condensed formulas in order to find the atoms implied in the line formulas.