Matter is anything that has mass and takes up space. All matter exists in one of four states or phases: solid, liquid, gas or plasma.

A pure substance cannot be separated into 2 or more substances by physical means. Pure substances have one set of physical and chemical properties. The particles of a pure substance are alike no matter where they are found.

A mixture is a combination of two or more pure substances that are not chemically combined. Mixtures are held together by physical forces and therefore can be separated physically.