Volcanoes

You can make your own volcanoes and explode them at home. To do this the boys took some old play-dough and shaped a volcano out of it. I had them put it on a plate or tray with sides. Then we put a little cup in the top center (the crater or vent). I filled the cup with a tablespoon or two of baking soda. Then I poured white vinegar into the cup. It fizzed and "exploded." We did this over and over, adding more baking soda as needed, until the plate or tray was filled with vinegar. You can also put the vinegar in first and then add the baking soda.
Some books have you built the volcano out of plaster of Paris. I just threw away the play-dough when we were done.