Some metals are not so dense, such as aluminium, which has different uses. Metals conduct electricity . Metals will always allow electricity to flow through them. Even mercury will. This is why wires and plugs and everything else in a circuit must be made of a metal.
Metals conduct heat energy .
Metals will allow heat to pass through them. This can be useful in places such as a frying pan when the heat from the cooker needs to get through to the food quickly, but it can also be dangerous. Metals are malleable. This means they can be hammered and bent into any shape that you want. They can easily be changed to do different jobs.