A candle and some rising colored water reveal a hidden property of air that’s around you all the time.
Watch closely and use everything you know about air pressure differences to explain the mystery of the rising water. Look for clues that explain why the water rises into the container. It may not be what you think it is so keep your eyes open as you collect data. The best part is that you’ll likely have to do the experiment several times to confirm how air pressure is involved.