$\text{Propan: }CH_3-CH_2-CH_3$
$\text{2- metylpentan: }CH_3-(CH-CH_3)-CH_2-CH_2-CH_3$
$\text{2,3 - đimetylbutan: }CH_3-(CH-CH_3)-CH_2-CH_2-CH_3$
$\text{3-etyl-2-metylpentan: }CH_3-(CH-CH_3)-(CH-CH_3)-CH_3$
$\text{Butan: }CH_3-CH_2-CH_2-CH_3$
$\text{3-metylpentan: }CH_3-CH_2-(CH-CH_3)-CH_2-CH_3$
$\text{Isobutan: }CH_3-(CH-CH_3)-CH_3$