What measures the ability of a liquid to change to a vaporous state?

The ability of a liquid to change to a vaporous state is referred to as volatility. This property indicates how readily a substance can evaporate, which is influenced by the liquid's molecular structure and intermolecular forces. Liquids with high volatility will evaporate quickly at room temperature, while those with low volatility will require higher temperatures to achieve vaporization. Understanding volatility is crucial in areas like fuel selection for aircraft engines, as highly volatile fuels may evaporate and create vapor-lock problems, while fuels with lower volatility may be less prone to such issues.

Viscosity measures a fluid's resistance to flow, density relates to the mass per unit volume of a substance, and solubility pertains to how well a substance can dissolve in a solvent. While all these properties are important in various contexts, they do not directly describe the process of a liquid transitioning into a vapor. This focus on boiling points and the tendency to evaporate highlights why volatility is the correct answer.