Which term describes a substance made of more than one element?

The term "composite" accurately describes a substance made of more than one element. Composites are materials formed by combining two or more constituents with distinct physical or chemical properties. The purpose of creating a composite is to leverage the best characteristics of each component, resulting in a material that has improved performance attributes compared to its individual components.

For example, reinforced concrete is a composite material, combining concrete (a mixture of different elements) with steel to enhance strength and durability. This concept applies broadly in materials science, where various elements and compounds are combined to achieve desired properties for specific applications.

While a mixture can also consist of multiple components, it does not always imply a uniform or bonded structure as found in composites. An elemental compound typically refers to substances formed from atoms of more than one element that are chemically bonded, but "composite" encompasses a broader range of material types, frequently applied in engineering and manufacturing. An alloy, which consists of two or more metals, is a specific type of composite, but does not encompass all possible materials made from multiple elements, making "composite" the most inclusive and accurate choice.