Which term describes a pure substance formed by the chemical combination of two or more different elements?

A compound is defined as a pure substance that results from the chemical combination of two or more different elements. This process involves a chemical reaction where the atoms of the different elements bond together, creating a new substance with unique properties that are distinct from the individual elements. For example, water (H2O) is a compound made from the elements hydrogen and oxygen, combined in a specific ratio to form a new substance.

In contrast, an element refers to a substance that cannot be broken down into simpler substances by chemical means and consists of only one type of atom. A mixture, on the other hand, is a physical combination of substances that retain their individual properties and can be separated by physical means. An alloy is a specific type of mixture consisting of two or more metals or a metal and another element, which does not fit the definition of a compound. Thus, the correct term for a substance formed by the chemical combination of different elements is indeed a compound.