Which term measures the thickness of a liquid?

Viscosity is the term that measures the thickness of a liquid, reflecting its internal resistance to flow. This property is essential in understanding how liquids behave under various conditions, such as temperature and pressure. A high viscosity indicates a thick liquid, like honey, which flows slowly, while a low viscosity indicates a thinner liquid, like water, which flows easily.

Viscosity is critical in various applications, such as in manufacturing processes where liquids are involved in mixing, transporting, or coating materials. Understanding viscosity helps engineers and designers choose the right fluids for specific applications, ensuring optimal performance and efficiency.

The other terms relate to different physical characteristics of substances. Density measures mass per unit volume, pressure refers to the force exerted by a fluid on surfaces, and fluidity describes how easily a fluid can flow, but does not specifically quantify thickness. Thus, viscosity is the most appropriate term for measuring the thickness of a liquid.