A compact disc contains an extremely thin sheet of aluminum. If you put a larger block of metal in a microwave oven along with a CD and turn the oven on, a) nothing significant happens b) only the metal will spark and then melt c) the metal will melt and the CD will spark d) only the CD becomes hot enough to soften and sparks dance about its surface I know that when you put a CD in a microwave D is what happens. I also know that if you put a large block of metal in the microwave nothing significant happens because thick metal conducts electricity well. But when you combine these two objects does anything different happen? My intuition is to go with D, since I don't think that the metal block would interfere with the microwaves that would cause the aluminum on the CD to spark, but I'm not entirely sure. One more quick question...if metal bowls would help reflect microwaves through the food, why are most microwave safe bowls glass (i.e. Pyrex)? Is it better to cook foods in metal bowls or glass bowls?