Why is aluminium a bad conductor?

Answer: If we compare it to other metals like gold, silver, and copper, aluminium is a poor conductor of heat and electricity. Overall, aluminium is a good heat and electrical conductor. Aluminium exhibits strong conductivity for electricity and heat because it contains three free electrons, but its conductivity is lower because it is less dense than copper. 

Noble metals like gold and silver are much more electrically conductive but cannot be employed in everyday items because they are pricey. Despite having a lower conductivity than gold and silver, copper is utilised extensively in home goods. Although aluminium is a poorer electrical conductor than copper, it is still commonly utilised in everyday items since it is less expensive.