Which property of a material indicates its ability to conduct heat?

The property that indicates a material's ability to conduct heat is thermal conductivity. This property quantifies how well a material allows heat to pass through it, which is crucial in various applications, including insulation, heat exchangers, and thermal management in engineering.

Thermal conductivity is typically measured in watts per meter-kelvin (W/m·K). A higher value means the material is more efficient at transferring heat. For instance, metals usually have high thermal conductivity, making them suitable for applications where heat transfer is necessary, such as cookware or heat sinks.

In contrast, the other properties listed, such as density, viscosity, and elasticity, pertain to different physical characteristics. Density relates to mass per unit volume, viscosity measures a fluid's resistance to flow, and elasticity describes how a material deforms under stress and returns to its original shape. None of these properties directly relate to the ability of a material to conduct heat.