Which property describes a viscous material?

A viscous material is characterized primarily by its resistance to flow. The key feature of such materials is their ability to deform under stress and the rate at which they do so.

When considering the correct answer, it’s important to focus on the nature of viscosity itself. Viscosity measures a fluid's internal friction and resistance to shear or flow. A material with high viscosity does not flow easily; rather, it tends to maintain its shape under normal conditions until sufficient force is applied.

In contrast, materials that stretch infinitely are typically associated with elastomers or elastic substances. While they can undergo significant deformation, the defining trait of viscosity is more about the flow under stress rather than the extent of stretch.

On the other hand, the ability to return to its original shape is indicative of elastic behavior, not viscous behavior. Viscous materials can deform and will not necessarily recover their shape upon removal of stress, contrasting with elastic materials.

The ability to conduct electricity pertains to the electrical properties of materials rather than their viscosity. While some viscous substances may conduct electricity, such as certain gels or ionic liquids, this is not a defining characteristic of viscosity.

Overall, the defining characteristic of a viscous material is its resistance to flow, making it less