After making instant snow and discussing polymers, turn the tables and warm up with the Quirkle Hallie Heat. Watch kids get excited as you make warm water rise to the top of a bottle and cold water sink to the bottom. This trick appears to be magic, but it's not; it's science!
Hallie Heat's Rising Water Experiment
To demonstrate how warm water will rise and cold water will sink
Two plastic water bottles (20 ounce)
Hot and cold water
Food coloring (any dark color)
Plastic mixing bowl
Fill one bottle to the top with cold water. Put a few drops of food coloring in the other bottle and add hot water. Let the water be as hot as it can be without burning you or melting the plastic bottle. Stand the hot water bottle in the plastic bowl. Place the index card over the mouth of the cold water bottle. Flip it over carefully. Put the cold water bottle over the hot water bottle so the mouths are lined up. Slide the card out.
The children will be amazed as the hot water rises from the bottom bottle into the top bottle. Cold water is denser and sinks. The cold water pushes the hot water beneath it upward.