Thermal diffusivity: nature and classification. Identify the most accurate description of thermal diffusivity (α = k/(ρ·cᵖ)). Select the correct statement.

Facts about thermal diffusivity
α = k/(ρ·cᵖ) has units of m²/s (not dimensionless).It is a material property and commonly varies with temperature (so it can be temperature-dependent).

Option analysis
A can be true in practice, but the safest classification is that α is a material property.C is incorrect because α is not dimensionless.D is therefore incorrect because it includes a wrong statement.

Final Answer
It is a physical property of a substance.