‘For all practical purposes: technologies of the elements’ considers the variety that exists within the elements, and how they can be applied to our everyday lives. Iron and steel gave early armies the edge in battle, but the role of carbon in steel production was not understood until the eighteenth century. Silicon was used in glass for centuries, but its semiconducting properties make it the ideal substance for computer chips. The platinum group metals were unsuccessfully marketed as alternatives to silver, but now they are integral in catalytic converters. Palladium gained notoriety as a key ingredient of ‘cold fusion’, and rare earth metals are used in television screens.