Metals are elements that have certain common characteristics, including:

* They are shiny.

* They are good conductors of heat and electricity.

* They are malleable, meaning they can be hammered into thin sheets.

* They are ductile, meaning they can be drawn into thin wires.

* They react with oxygen to form oxides.

Aluminum has all of these characteristics. It is a shiny, silver-white metal that is a good conductor of heat and electricity. It is malleable and ductile, and it reacts with oxygen to form aluminum oxide.