Fill a Styrofoam cup with very hot water (or coffee). Take objects made of different materials such as a metal spoon, a wooden pencil, a plastic pen, or a glass rod. Put one end of each object into the water and make these observations:
a. How close to the surface of the water do you have to hold the object for it to feel noticeably warm to the touch?
b. From your observations, which material would you judge to be the best conductor of heat? Which is the worst? Can you rank the materials according to their ability to conduct heat?