Use your knowledge of electronic structure to explain why aluminum is a metal.
The reason aluminum is classified as a metal is because it of it's valence or outer electrons. Aluminum has three valence electrons, and it loses all three to form the ion Al3+. Metals are elements that have a high tendency to lose electrons, forming postive ions. In doing so they achieve the stable electron configuration of a noble gas. Metals are found in Groups 1-12 on the periodic table and in parts of groups 13-16. In Group 13, Al, Ga, In and Tl are metals.
Aluminum exhibits the properties typically associated with metals. It's a good conductor of electricity and heat. It's malleable, meaning it can be deformed into thin sheets and it's ductile, meaning it can be stretched into wires. Aluminum is also shiny like other metals. These properties are a result of metallic bonding. The positive nuclei of electrons are surrounded by a sea of mobile, loosely attracted valence electrons. The mobility of these electrons allows charge to move through a metal and it allows metals to be deformed without fracturing.