Key terms including chemical element, group, period, chemical property and physical property, melting point and boiling point, alkali metals, halogens and noble gases, metal, non-metal and metalloid, malleable, ductile and brittle. Explanation of metals, non-metals and metalloids. Explanation of the typical properties of metals and non-metals. Explanation of the alkali metals, the halogens and the noble gases. Explanation of displacement reactions.