Let’s see how you did! If you didn’t get a few of these, don’t let it stress you out – it just means you need to play with more experiments in this area. We’re all works in progress, and we have our entire lifetime to puzzle together the mysteries of the universe!


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2 Responses to “Answers to ‘Molecules’ Exercises”

  1. Good question! Physical change would be your teeth grinding the food down, but a chemical change happens in the stomach when the strong acids combine with the food to break it down. Your body does a chemical change on the food, but your mouth does the physical change to get it into the right shape to fit down your throat. Does that help?

  2. Lynn Woitalla says:

    Question by Jacob:

    RE: Chemical vs. Physical changes

    Some things are obviously chemical or physical changes. But what about eating? Chewing food would just be a physical change – it’s just breaking the food into smaller pieces of the same thing. But what about the process of digesting food? Doesn’t food change as your body processes it? As the body breaks food down, it there any chemical reaction taking place or is it all physical??