* Evaporation is based on volatility: Volatility refers to how easily a substance changes from a liquid to a gas. Highly volatile substances evaporate quickly at room temperature (like gasoline). Less volatile substances evaporate very slowly or not at all at room temperature.

* Oil variety: Oils can vary greatly in their chemical composition, which affects their volatility. For example:

* Volatile Oils: Essential oils extracted from plants (like lavender, peppermint) are highly volatile and evaporate readily.

* Semi-volatile Oils: Some vegetable oils (like olive oil) have moderate volatility and evaporate slowly over time, especially when exposed to heat or air.

* Non-volatile Oils: Mineral oils (like petroleum jelly) have very low volatility and don't evaporate significantly at room temperature.

In summary: While some oils evaporate readily, others are quite stable and won't evaporate noticeably in normal conditions. The evaporation rate of an oil depends on its chemical composition and the surrounding temperature.