Matter is anything that takes up space and has mass; organisms are composed of matter. Examples include rocks, metals, oil, gases, and living organisms.
An element is a substance that cannot be broken down into other substances by chemical reactions. Today, chemists recognize 92 elements occurring in nature. Examples: Gold, Copper, Carbon, Oxygen.
Each element has a symbol, usually the first letter or two of its name; some symbols are derived from Latin or German (e.g., Sodium is \mathrm{Na} from natrium).
A compound is a substance consisting of two or more different elements combined in a fixed ratio. Example: table salt, sodium chloride, \mathrm{NaCl}, in a 1:1 ratio.
Caution: The transcript states that pure sodium and pure chlorine form water; that is incorrect. They form