# What is different about the three isomers of pentane?

We have ${C}_{5} {H}_{12}$, and form this formula we get structural isomers of $\text{n-pentane}$, H_3C-CH_2CH_2CH_"CH_3, $\text{isopentane}$, ${H}_{3} C - \left({H}_{3} C\right) C H C {H}_{2} C {H}_{3}$, and $\text{neopentane}$, ${\left({H}_{3} C\right)}_{4} C$.
In each isomer, the connectivity of the carbon-carbon chain is different. The isomers would have slightly different metling and boiling points, with $\text{n-pentane}$ as the LEAST volatile. Why so?