The only way to move heat energy in a vacuum is via radiation.
Vacum
A nonmetal would make a good insulator.
Fiberglass is an insulator. Its properties make it a good electrical insulator because it does not conduct electricity well.
rubber
a poor thermal conductor.
In a thermos ther is a vacum between the metal and the glass inner container. since there is this vacum heat can't excape easily and is mostly lost at the top where the glass and metal connect (same for cold liquids and food). Also, heat and colder temps cant enter the thermos making it a very good insulator.
it depends what type of insulator youre talking about. wood is a good thermal insulator and rubber is a good electrical insulator A perfect vacuum is the best insulator.
insulator
i think it does because it sure doesn't make a good conductor.
a poor thermal conductor.
wool holds lot of air.air being bad conductor of heat make the wool a good conductor of heat.
Yes it is a good insulator