Final answer:
A liquid is considered volatile if it has a relatively high vapor pressure and tends to evaporate readily. Volatile liquids have high vapor pressures and evaporate faster, while nonvolatile liquids have low vapor pressures and evaporate slower.
Step-by-step explanation:
A liquid is considered volatile if it has a relatively high vapor pressure and tends to evaporate readily. Volatile liquids have molecules that can escape into the vapor phase and diffuse through the gas phase away from the container. On the other hand, nonvolatile liquids have low vapor pressures and evaporate more slowly. For example, diethyl ether, acetone, and gasoline are volatile liquids, while mercury, ethylene glycol, and motor oil are nonvolatile liquids.