Object: a transparent bowl of water, a vial of food coloring, a spoon

Good morning, boys and girls. Have you ever played with food coloring? It's pretty fun, isn't it? It's amazing how just a little tiny bit of food coloring can spread its color so quickly. For instance, let's say I take this bowl of water. The water is clear, no color to it, right? Now I'll just put 2 or 3 drops of food coloring in it, stir it up a little bit, and presto! Look, the water is (name the color you just put in). Just a second ago, t…