Which term describes the ability or tendency of an object to float in water or other fluids?

Buoyancy refers to the ability of an object to float in water or other fluids. This phenomenon is a result of the gravitational force acting on the object and the upward force exerted by the fluid. An object is buoyant when the upward force of the fluid is equal to or greater than the weight of the object itself. The concept of buoyancy is grounded in Archimedes' principle, which states that any object submerged in a fluid experiences an upward force equal to the weight of the fluid displaced by the object. This principle helps to explain why some objects float while others sink, depending on their density relative to the fluid.

Density, while related, specifically refers to the mass of an object per unit volume and does not directly describe the ability to float. Viscosity defines a fluid's resistance to flow, whereas affinity implies a natural attraction or tendency towards something, neither of which relate to floating.