One of my favorite activities was helping preschoolers do interactive science experiments. 


In one activity, we helped the preschoolers investigate the science behind syphoning liquids.  Since the height of the tube inside the beaker is shorter than the height of the tube coming out of the beaker, the water outside the beaker pulls the water inside the beaker right out of the beaker.  Thus, syphoning allows us to “pump” the water out of the beaker without using any energy!  Pretty cool, huh?


In this experiment the kids investigate floatation in fluids of different densities.  Saltwater is denser than freshwater, so the egg will float in saltwater but not in freshwater!
