Here's why:

* Nonane is a hydrocarbon: It's a chain of 9 carbon atoms with hydrogen atoms attached.

* Hydrocarbons have varying boiling points: The length of the carbon chain influences its boiling point. Longer chains mean stronger intermolecular forces, leading to higher boiling points.

* Nonane's boiling point is relatively high: Nonane has a boiling point of around 150.8 °C (303.6 °F).

* Room temperature is much lower: Room temperature is typically considered to be around 20-25 °C (68-77 °F).

Therefore, nonane is a liquid at room temperature. It would need to be heated significantly above room temperature to become a gas.