All metals are good conductors of electricity. This is one of the earliest things we learn in Science. What we often do not know, is why they are so good at it! The answer lies in how metals, and therefore Aluminum, are atomically structured.
But first, a word on electricity conduction is in order. What do we mean by it anyway? Electricity is the flow of electrons. When we provide a potential difference between two end states, electrons from one state flow to another, and hence create electricity. Conductivity is the ease with which these electrons can flow. A good conductor will facilitate electron flow, while an insulator would hamper it.
Aluminum is a good conductor because it allows for electron flow. All metals are arranged with what is regarded as metallic bonding. Within the atom of a metal, there exists a â€˜sea of electrons’ which is free to move about. These electrons do not belong to a particular atom but can move about other atoms as well. So when a potential difference is applied to the Aluminum, these electrons flow rapidly and cause â€˜electricity’. Incidentally, metals are also good conductors of heat for a similar reason. In contrast, an insulator, such as glass, has a rigid structure with tightly bound electrons. It, therefore, does not conduct electricity in a desirable manner. In the modern age, technological advances have allowed the synthesis of superconductors which can even outdo the conduction of metals!
So simply put, Aluminum conducts electricity because it is a metal. Metals have atomic structures surrounded by free-roaming electrons, which can flow easily. We use metals in a number of places where electricity is to be used, particularly in the wiring.