Condensed structures are easy to read and draw

Compare the condensed and expanded structural formulae shown below.

In condensed structures

carbon-hydrogen bonds are not shown.
Each carbon is followed directly by the hydrogen atoms bonded to it, the number of hydrogens being shown by the subscript.
carbon-carbon single bonds are not shown for carbon chains written on the same line.
Be careful to draw the bonds from chain to branch atoms from C to C. These are the carbon atoms bonded to each other.
carbon-carbon multiple bonds are always shown using two or three lines, as appropriate.

Multiple-bonded carbons are bonded to fewer hydrogen atoms.

1 CH₃CH₂CH₃	2 CH₂=CHCH₃

3 HC≡CCH₂CH₃	4

If the carbon atom at the end of the chain is

single-bonded it has 3 hydrogens (as in 1-4).
double-bonded it has 2 hydrogens (as in 2).
triple-bonded it has 1 hydrogen (as in 3).