Question

what is the best definition of a mixture? a mixture is when elements combine. a mixture is a change that makes new molecules. a mixture is a combination of two or more substances.

Explanation:

A mixture is formed when two or more substances are combined physically, without any chemical reaction creating new substances. Elements combining can form compounds via chemical reactions, and a change that makes new molecules is a chemical reaction. The correct definition focuses on the combination of substances.

Answer:

A mixture is a combination of two or more substances.