What is the extended and shortened structural formula for 2-methylpentane

The structural formula for 2-methylpentane is in Figure 1. It shows all the C-C and C-H bonds explicitly.

The bond-line formula for 2-methylpentane is in Figure 2. We assume that a carbon atom is at the ends and junctions of the lines. We do not show the H atom, but we mentally assume that there are enough to give each carbon a valence of four.

A condensed structural formula is designed to be typed all on one line. We could write the condensed structural formula for 2-methylpentane as either (CH₃) ₂CH-CH₂-CH₂-CH₃ or CH₃CH (CH₃) CH₂CH₂CH₃.

The horizontal C-C bonds are optional - you can include or omit them as desired.