How to look like a chemist: Drawing chemical structures

Chemists often don't show all the hydrogen atoms in a molecule, since they can clutter up the picture (and often aren't involved in the reaction). Often they use representations that omit the carbons, assuming that carbons are at the end of any line segment (see the structure on the far left). If they want to indicate hydrogens, often they will embed the H's with the carbons, as in the middle structure. The structure at the far right is unlikely to be drawn by a practicing chemist - who would use either of the two models on the left!