Have you ever seen a volcano erupt, maybe on television or in a movie? You can make your own small-scale eruption right in your kitchen! Or, if the weather is nice, this is a great outdoor project.
Nothing much happened when you mixed the vinegar, water, dish soap, and food coloring. It was sort of like your volcano was "dormant" or asleep. When you dropped the packet of baking soda into the bottle, the vinegar soaked through the tissue paper and reacted with the baking soda and your volcano became active and had a big eruption! When the vinegar and baking soda mixed, they formed a gas called carbon dioxide. This gas created lots of little bubbles that quickly filled the bottle and overflowed and spilled down the sides of the mountain, similar to the way lava would erupt and flow out of a volcano. The red food coloring turned the bubbles red to look more like lava, and the soap helped create even more bubbles to erupt out of your volcano. Try dropping another packet of baking soda into your volcano once the first "eruption" slows down and see what happens. Was there enough vinegar left to cause another reaction? If nothing happens, all of the vinegar was used up in the first reaction, so pour a little more vinegar into the bottle to see it react again. Since this project is pretty messy, the best way to clean up is to dump everything out of the pie plate into the trash can.
The outer shell of the egg is similar to the earth's crust. When you cracked the shell into several large pieces, those pieces were similar to the tectonic plates on the earth's surface. Notice how the pieces stayed together even though they were separate. That's exactly how the earth's plates work - they can move around a little bit, but they all stay in the same general spot attached to the next layer of the earth. The middle white part of the egg represents the earth's mantle. The earth's mantle is much harder because it is made of rock. The inner yellow part - the egg yolk - represents the earth's core. The earth's core actually has two parts - the liquid outer core and the solid inner core. Read this Science Lesson to find out more about the layers of the earth!