Aluminium
Aluminium is in the main subgroup of group III, period 3, has 3 electrons in its outer shell and shows the oxidation state +3 in compounds (Al³⁺). It is the most abundant metal in the Earth's crust and occurs in nature only as compounds: bauxite, alunite, kaolin (clay), feldspar. In industry pure Al₂O₃ (alumina) is separated from bauxite and electrolysed dissolved in molten cryolite Na₃AlF₆ at about 950 °C, because cryolite sharply lowers the melting temperature. At the cathode Al³⁺ + 3e⁻ → Al; at the anode oxygen is released and burns the carbon anode to CO₂; the overall equation is 2Al₂O₃ → 4Al + 3O₂ (electrolysis). The process needs a great deal of electricity, so it is done where electricity is cheap. Aluminium is light (density about 2.7 g/cm³) and conducts electricity and heat well, so it is used for wires, aircraft and car parts, cookware and foil.
Find aluminium objects (wire, foil, cookware, window frame) and make a table: “Object” and “Property that makes it suitable” (lightness, heat conduction, corrosion resistance). Do not test aluminium with acids or alkalis at home.