Cambridge Science – States of Matter Practice Test

Pure describes something that is not mixed with anything else. A pure substance has a uniform composition and consists of only one kind of material, whether it’s an element like gold or a compound like water. Because nothing else is present or blended in, its properties are consistent throughout.

A mixture, on the other hand, contains two or more substances that can be separated by physical means. A solution is a type of mixture where a solute is dissolved in a solvent, giving a uniform composition but still made from more than one substance. A compound is a pure substance too, but it is a single chemical substance formed from two or more elements bonded together, which is a more specific kind of purity than “not mixed with anything else.”