Inorganic nonmetallic hard and brittle materials include which option?

• A. Polymers
• B. Metals
• C. Ceramics
• D. Composites

Answer: (C)

Hardness with brittleness is a defining feature of ceramics. Ceramics are inorganic, nonmetallic compounds that form rigid lattices with strong ionic or covalent bonds. These bonds create high hardness and stiffness, and they can withstand high temperatures, but they restrict plastic deformation. When stress is applied, cracks tend to form and propagate through the lattice, leading to fracture rather than yielding. Polymers are organic and often more flexible or tough, metals are generally ductile due to metallic bonding, and composites vary in behavior; the classic example of inorganic nonmetallic hard and brittle material is a ceramic, such as alumina, silicon carbide, silica, or zirconia.