Styrofoam is the best material to use as an insulator. Styrofoam is the best insulator, since the temperature of the water in the styrofoam glass decreased the least. If you mean what "state" of matter is the best insulator then you're probably looking for gas as the answer. The state of matter that is best as a thermal insulator is gas.
its an insulator
Pure water is an insulator, but in the "real world", water usually has impurities - notably ions - that actually make it a good conductor. This is theory; I don't think it is practical to use water as an insulator.
A goose down jacket. Air gets trapped in between the goose feathers and acts as an insulator.
insulator
That wire could use a better insulator.
An insulator prevents electricity from flowing.
a pencil eraser is a conductor .
You need help
Birds use their feathers as an insulator by fluffing their feathers in winter to trap a layer of air in and around.
No. Electricity will flow right through it! So don’t use it as an insulator!
Insulator, unless you use the metal hanging part.
answer
To isolate hot terminals
to make an insulator prevent ice from not melting is to use tinfoil and dirt.
If you use a glass jar, it is already an insulator
For insulating a current you can use plastic/rubber.