Place a swatch of steel wool inside a glass beaker and cover with vinegar. Allow the vinegar to soak into the steel wool for one minute before removing the steel wool and draining the excess vinegar. Wrap the steel wool around a thermometer and place both into a second, clean beaker. Cover this beaker with a lid or piece of paper, but position the thermometer in a manner that allows you to continue reading the temperature. Check the temperature periodically for five minutes. The vinegar removes the steel wool's outer coating, triggering oxidation, a chemical reaction between iron and oxygen. Oxidation generates heat.
Using a blender, blend red cabbage and a little water into a liquid or simply use the juice from a jar of pickled red cabbage. Pour a small amount into a shallow bowl. Sprinkle a pinch of baking soda into the juice and watch it turn into green foam. After the red juice turns entirely green, add several drops of vinegar and watch as pink foam forms. The juice eventually turns red again. The coloring in red cabbage juice is a chemical that detects acids and bases. Bases, like baking soda, turn this chemical blue-green, while acids, like vinegar, turn it red.
Fill four glasses with three tablespoons, or 45 milliliters, of water each. Add one tablespoon, or 15 grams, of sugar to the first glass, two tablespoons to the second, three to the third and four to the last. Stir each using clean spoons. Fill a quarter of a separate, clean glass with the solution containing four tablespoons of sugar. Afterward, slowly and carefully pour the same amount of the three tablespoon solution into the same glass. Repeat this with the two and one tablespoon solutions. The layers should remain separate and distinct, as each has its own density and lighter densities float above heavier densities.
Fill an empty soda can a quarter way full with water. Using a hot plate or kitchen stove, heat the can until the water inside boils. Carefully grab the can while wearing an oven mitt or using kitchen tongs. Quickly dunk the can, upside-down, into a large beaker or kitchen pot filled with cold water. The can crunches up with a loud pop. The steam produced by the boiling water inside the can condenses the moment the can hits the cold water, causing the can to implode.