For the following descriptions, please write "CC" for chemical change, and "PC" for physical change: melting ice

burning popcorn

digesting food

molding clay

What are the 4 phases of matter in order of increasing engery content?

At 20°c, a sample of h2o liquid and a sample of co2 gas each have the same average kinetic energy. why is one a liquid and the other a gas at this temperature?

Some liquids can be distilled, but only at temperatures that are so high that it is impractical, or so high the compound decomposes. explain why distillation such compounds at significantly less than atmospheric pressure (some degree of vacuum) would solve this problem.