For Pre-K students the rain in a jar science experiment is fun and engaging plus it helps with their fine motor skills. You will need a jar, a small cups, food coloring, pipettes, shaving cream and water. Mix some water with food coloring in small cups, then fill the jar with water about 3/4 full. When the kids are ready to do the experiment add a bunch of shaving cream in the jar that was filled with water. The kids will be able to pick the colored water and use the pipettes to squirt the colored solution on top of the shaving cream cloud. The water will make its way through the shaving cream and into the water.