Which term describes a substance that contains more than one element?

The term that accurately describes a substance containing more than one element is "compound." A compound is a specific type of chemical substance formed when two or more different elements chemically bond together in fixed proportions. For example, water (H2O) is a compound composed of hydrogen and oxygen elements.

While "molecule" might seem like a plausible answer, it is important to note that molecules can consist of the same type of element as well (for example, an O2 molecule consists of two oxygen atoms). Furthermore, "element" refers to a substance that consists of only one type of atom, while "atom" is the simplest unit of matter, which cannot be divided into smaller substances without losing its chemical properties. Thus, "compound" is the most accurate choice to describe substances composed of more than one element.