Elements that react to form positive ions are metals. Elements that do not form positive ions are non-metals. The majority of elements are metals. Metals are found to the left and towards the bottom of the periodic table. Non-metals are found towards the right and top of the periodic table. Students should be able to: • explain the differences between metals and non-metals on the basis of their characteristic physical and chemical properties. This links to Group 0 (page 24), Group 1 (page 24), Group 7 (page 25) and Bonding, structure and the properties of matter (page 26) • explain how the atomic structure of metals and non-metals relates to their position in the periodic table • explain how the reactions of elements are related to the arrangement of electrons in their atoms and hence to their atomic number.