Metals are everywhere in the modern world, from the aluminium in an aircraft fuselage to the copper in electrical wiring to the steel in a bridge. Their dominance in engineering and technology is no accident; it is a direct consequence of their remarkable physical and chemical properties. This chapter explores those properties in depth, and examines how we obtain, protect and make use of metals in practice.

We begin by comparing the general physical and chemical properties of metals and non-metals, before looking at how metals react with dilute acids, water, steam and oxygen. This leads into the reactivity series, which ranks metals in order of their tendency to form positive ions, and allows us to predict and explain the outcomes of displacement reactions. We also consider the apparent unreactivity of aluminium, which despite being a highly reactive metal is protected in practice by a thin but tenacious layer of aluminium oxide.

We then turn to alloys, which are mixtures of a metal with other elements, and examine how the disruption of the regular metallic lattice by differently sized atoms makes alloys harder and stronger than the pure metals they are made from. From there, we look at corrosion, focusing on the rusting of iron and the various methods used to prevent it, including barrier methods and sacrificial protection using zinc.

The chapter closes with the extraction of metals from their ores, where we connect the method of extraction to the position of the metal in the reactivity series. We look in detail at the extraction of iron in the blast furnace and the extraction of aluminium by electrolysis, including the role of cryolite and the reactions at each electrode.