a) A substance is a material where all particles share the same properties. b) A mixture is a combination of two or more substances. c) An element is a substance that cannot be broken down into smaller particles. d) A compound is a combination of two or more elements in a fixed ratio.
Work Step by Step
a) An example of a substance is gold or water. b) An example of a mixture is salt water or trail mix. c) An example of an element is oxygen or argon. d) An example of a compound is $CO_2$ or $HNO_3$.