water
Depends what's in your gravel. In order of best to worst: Sandstone 1 Limestone Concrete Water Soil ref:http://en.wikipedia.org/wiki/List_of_thermal_conductivities
Silver is the best conductor there is, no matter what it is made into.
Air (Explanation): water has a high specific heat capacity, but it can boil. stone (😂) also is a good thermal insulator, but it can get really hot. Metal is a very good thermal conductor, so it is definitely not that. Therefore, air is the best (its also really hard to boil).
Duct Tape is made of rubber and since rubber is a good insulator that makes duct tape a good insulator. The best tape for insulating is electrical tape.
wool i think.
nitrogen
Tinfoil
Distilled water is the best insulator for listed choices because it has no ion's in it.
With tonic water and some alchohol.
no! its a insulator
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.
That is entirely a matter of opinion.
wool insulates heated water best because woll is the best insulator.
oxygen.is the best insulator
70%alchahol or 90% alchohol
No. If you can get it, vacuum is the best insulator.
The best insulator of heat is probably polystyrene foam or fiber glass.