a brick
polysterene?
The best heat insulator is granetino - a chemical plastic. You cannot find it to buy though, you must order it, have it shipped over, and can only buy it in bulk for factories. Carter
water
Aluminum will conduct both electric current and heat, so it would be a bad insulator of either.
The best insulator of heat is probably polystyrene foam or fiber glass.
a potato is not an heat insulator because it's skin,but if you take the skin off it will be a heat insulator
it is good heat insulator, as it has air in it. as air is a good insulator of heat, the sponge, which has lots of pockets of air also becomes a good insulator
Air is the best heat insulator, provided you can prevent it from transferring heat by convection. This is normally made into use in double-glazed windows.
Nitrogen is not a good insulator of heat. It is a poor conductor of heat, but it is not an effective insulator as it does not trap heat well and can easily transfer heat through convection or conduction.
Vacuum is a better insulator than fiberglass. Vacuum has no particles to transfer heat through, while fiberglass relies on slowing down heat transfer through its material. This makes vacuum a more effective insulator, as it minimizes heat transfer through conduction and convection.
Don't know if it is the best but Newspaper is a very good insulator and generally easy and cheap or free to get. Cardboard is alo very good.
An insulator. More specifically, a thermal (heat) insulator, as opposed to an electrical insulator, which suppresses the flow of electricity.