Aluminium when bared to air, generates a protective layer of aluminium oxide on its surface which works as a powerful resistant to corrosion. This is one primary reason for its wide usage for external applications. Though it is less resistant to alkali, the metal is a good resistant to acids. Electrical conductivity: The metal comes with high conductivity properties that enables it to be used as an electric conductor. It has the capability to conduct twice the capacity of electricity than the other commonly used metals. Density: The metal has lower density in comparison to steel, copper etc. and this makes it a lightweight metal which allows greater workload capabilities at lower costs.