ADM 6th grade students spent a day in science class investigating sublimation by experimenting with the strange properties of dry ice. Dry ice is very cold carbon dioxide which is solid at -109 degrees Fahrenheit. It has no liquid phase, so it sublimates directly from a solid to a smoky fog-like gas, which flows downward instead of up because it is heavier than air. DeSoto 6th graders have been learning about the difference between phase changes and chemical reactions, and how the Law of Conservation of Matter applies to chemical reactions.