Grouping atoms with the condensed structural formula

We like the Lewis formula because it enables you to show a lot of information without having to write all those little dots. But it, too, is rather bulky. Sometimes chemists (who are, in general, a lazy lot) use condensed structural formulas to show bonding patterns. They may condense the Lewis formula by omitting the nonbonding electrons (dots) and grouping atoms together and/or by omitting certain dashes (covalent bonds). For instance, condensed formulas often group all the hydrogens bonded to a particular carbon atom. Figure 1-1 shows a couple of condensed formulas for C₂H₄O.

Figure 1-1: Condensed structural formulas for C₂H₄O.