Volcanoes!

No unit on Dinosaurs would be complete without learning about volcanoes.  This is probably the one activity that kids remember the most about Preschool at Linda's.  I've had some 3rd and 4th graders that still ask if they can do volcanoes in the sand outside.
Since snow was covering the ground and we didn't want them sitting in the snow we experimented with the erupting process indoors.
We had small pill bottles that they pretended were little volcanoes.

We added  food coloring to squeeze bottles of vinegar. (We used bottles that come with tie dye kits and ketchup and mustard bottles that are often used on picnics)    We used red, yellow, blue, green and purple food coloring for coloring mixing experience as well as observing the reaction of baking soda and vinegar.

The children spooned baking soda into the bottle and squeezed the vinegar in until it bubbled over.

We brought out a bucket and dumped the tin trays as they filled up so we wouldn't have any major spills.

Sometimes the baking soda built up inside the bottle.

Some of the children would have kept working for hours if we would of had the time and supplies. It's not uncommon for us to go through a jug of vinegar and a couple boxes of baking soda when we experiment with volcanoes.   A couple years ago we made volcanoes out of chicken wire and duct tape.  We had pvc pipe inserts and ping pong balls to fit on top so that when it erupted the ping pong balls flew up in the air.  I don't have any pictures of those right now.  They are in need of revamping so maybe that can be a summer project for us.