On Monday my husband and kids were doing a Halloween experiment.
You get 1/4 cup cornstarch, 2 tablespoons water, green food coloring to desired color, and a pinch phosphorescent powder, then mix it all together. Then you charge it with a flash light and you have "Alien Ooze".
This is a fun experiment with kids because, if you put your fingers into the concoction slowly, it is liquid in state and sticks to you like liquid does. If you hit it hard with your fingers, your fingers can't even penetrate the surface of the mixture. The kids where real intrigued by the whole thing. The interesting part is that you can do both at the same time. One kid can hit it; at the same time another kid is putting their fingers in slowly, and both reactions are happening simultaneously, within inches of each other.