What do you call a material composed of two or more constituents with different properties?

• A. Alloy
• B. Mixture
• C. Composite
• D. Solution

Answer: (C)

Combining two or more constituents with different properties to create a material that retains those constituents and delivers tailored performance is what a composite does. In a composite, the components stay distinct and work together to give properties—like higher strength, stiffness, or toughness—than any one component alone. Classic examples include concrete (cement matrix with aggregates) and fiberglass (glass fibers in a polymer matrix), where the overall material benefits from the strengths of each part.

This differs from an alloy, which is typically a metal or metal-plus-element mix that forms a largely uniform material at the microscopic level, not distinct phases with separate identities. It also differs from a mixture or a solution, where components may blend without creating a new material with engineered, phase-structured performance. A composite is specifically about combining constituents with different properties to achieve a material with enhanced, customizable characteristics.