| ||Metals can readily form alloys with iron because their atoms are a similar size. The atoms of other metals simply replace atoms of iron in the metal lattice. Each metal atom contributes outer electrons to the cloud of delocalised electrons and becomes a positive ion. Attractions are formed between positive ions and electrons in exactly the same way as happens with the pure metal. |
However, the presence of a relatively few other ions can significantly change the properties of the material. Steel, for example, is much harder and stronger than pure iron.
[See page 11 for more about alloys.]