Understanding chemical and physical changes is a strange part of science. Once you learn to use chemical equations, it is so simple that no one even thinks about it. Before you learn to use chemical equations, it is so complex that most people don't really understand it. For a better view of that, you might also read Changing How We Look at Changing.
A catalyst is a substance that takes part in a chemical reaction, causing it to happen faster, but the catalyst is not used up by the reaction. There is just as much left afterwards as there was before the reaction began.
This experiment is a classic. If I had to pick the one science experiment that I have seen in the most science books, this now would be it. But it is also a very misunderstood demonstration. You will find that even many books of science experiments get the explanation for this one wrong.
This experiment comes from my neighbors at the Malibu Creek State Park campground. While taking my morning walk, I heard a lady bragging to her husband that she started the campfire with only one match. That made me think of the fellow that I watched the night before as he poured two bottles of charcoal lighter fluid onto a pile of wood and still failed to get the fire going. He would pour on the liquid and get a huge blaze, which quickly died. How could the heat of one match work better than a gallon of blazing lighter fluid?
This time we will take a look at the science of cooking green vegetables. Now, some of you may be saying "Ick!", but even if you don't like to eat them, it is still interesting to watch them cook. Also, knowing some of the science may interest you enough to give them a second chance, and you may discover how delicious they are.