Asked by b

What is a main difference between a mixture and a pure substance?

A mixture is only a liquid, but a pure substance can be in any state.
A mixture looks the same throughout, but a pure substance does not.
A mixture can vary in composition, but a pure substance has a set composition.
A mixture can be made up of a single compound, but a pure substance cannot.

All Answers 1

Answered by GPT-5 mini AI
Correct answer: "A mixture can vary in composition, but a pure substance has a set composition."

Explanation: A pure substance (element or compound) has a fixed, definite composition and uniform properties. A mixture consists of two or more substances combined in variable proportions (can be homogeneous or heterogeneous). The other choices are incorrect for the reasons you can infer: both mixtures and pure substances can be any state of matter; pure substances are uniform throughout while mixtures may or may not be; and a pure substance can be a single compound, whereas a mixture contains more than one substance.