Almost all iron is used in the form of an alloy. State the name of the most common type of iron alloy and the other element that is an essential component of these alloys.

Name:

Other element:

An early alloy of aluminium was Duralumin which contained small quantities of copper and magnesium. This is stronger and more rigid than pure aluminium. Explain on an atomic level why the addition of other elements has this effect.

Name: steel and other element: carbon;

atoms/ions of the alloying element are a different size/larger/smaller;

prevents the layers of atoms/ions sliding across each other;

This question was generally answered correctly.

Part (d) proved to be most challenging although it deals with the fundamental idea of the behaviour of alloys.