Metals consist of giant structures of atoms arranged in a regular pattern. The atoms sit in layers, one above another, in a repeating arrangement.
The electrons in the outer shell of metal atoms are delocalised. This means they are not held by one atom but are free to move through the whole structure. The sharing of these delocalised electrons gives rise to strong metallic bonds, because the electrons are attracted to the positively charged parts of the structure.
Metallic bonding occurs in metallic elements, such as iron and copper, and in alloys, which are mixtures of a metal with other elements. The bonding in a metal can be represented as a regular pattern of positive metal ions surrounded by a shared pool of delocalised electrons.
