Why does aluminum conduct heat and electricity well?

Aluminum is an excellent conductor of heat and electricity primarily due to the nature of its metallic bond. In metallic aluminum, atoms donate their three valence electrons to a common pool, where they become nonlocalized conduction electrons.12

These electrons are free to roam throughout the crystal structure, acting as mobile charge carriers. When an electrical field is applied, these free electrons move easily through the solid, facilitating the flow of electric current.123

The efficiency of this conduction depends on both the number of available electrons and their mobility—the ease with which they travel through the lattice. While aluminum has three conduction electrons per atom, its overall conductivity is also influenced by how these electrons interact with the crystal lattice and any potential defects or impurities that might cause scattering. Because these valence electrons are not bound to specific atoms, they are also highly effective at transporting thermal energy throughout the material.1324