1.46 Understand that a metal can be described as a giant structure of positive ions surrounded by a sea of delocalised electrons

A metal has a giant structure, meaning that it's made up of hundreds and thousands of positive ions. These are surrounded by a 'sea' of delocalised electrons. This means that they aren't 'bound' to any particular atom and are free to roam within the structure.

Source: BBC Bitesize
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