What characteristic describes brittleness in materials?

Brittleness in materials is characterized by the tendency to break into sharp shards. When a brittle material is subjected to stress, it generally does not undergo significant deformation. Instead of bending or stretching, it fractures suddenly, often resulting in sharp, jagged edges. This property is critical in engineering and material selection, as it influences the safety and performance of structures and products.

The other characteristics listed do not accurately describe brittleness. For instance, the ability to deform without breaking reflects ductility rather than brittleness. Additionally, the capacity to withstand compressive forces pertains to the material's strength and resilience under pressure, which is not a direct indicator of brittleness. The ability to conduct electric current relates to the electrical properties of materials, which is also unrelated to the concept of brittleness. Focusing on sharp fragmentation when broken is what distinctly defines a brittle material's behavior under stress.