Which description defines a chemical element?

Prepare for the American Water Works Water Treatment Plant Operator Test. Study with multiple choice questions, each with hints and explanations. Get ready to excel!

An element is a pure substance made of only one kind of atom. That single-type-atom nature defines it, and it’s typically described as a substance that cannot be broken down into simpler substances by chemical means. Mixtures contain more than one substance, so they’re not pure substances. Compounds are also pure substances, but they’re made from two or more elements bonded together, not just one kind of atom. So the description that best defines a chemical element is a pure substance composed of only one type of atom.