Dry ice is solid carbon dioxide. Have you ever wondered what would happen if you microwaved dry ice? Here's your chance to find out, without risking your microwave!
First I've compared dry ice in water, in the microwave compared with left out on the countertop. The microwaved dry ice in water is nearly gone after a minute in the microwave because the microwave heated the water, causing the dry ice to sublimate more quickly.
Next I compared dry ice on a plate in the microwave to dry ice left on the counter. Although the microwaved plate became very hot, the dry ice was unaffected. The microwaved piece of dry ice and the control piece of dry ice were comparable in terms of shape and size.
The reason why dry ice is unaffected by microwaves is because carbon dioxide is a linear molecule with no electrical polarity. The electromagnetic waves given off by the microwave don't really interact with the nonpolar molecule, so nothing happens.