Cloud in a Jar Update
Part of this experiment might look familiar; we’ve done a different version of this before! But today we are taking it to the next level.
What You Need:
-clear jar with a lide
-blue food coloring
-small bowl with ice
-black paper or other dark background
-hairspray
-hot water
What to Do: Click here to watch my video demonstration
-Place the jar in front of your dark background to help you see this experiment better
-Add 1”-2” of hot water and the food coloring into the jar
-Quickly spray hairspray into the jar and seal it with the lid. You don’t need much hairspray, I suggest holding down the nozzle for one second
-Place the bowl of ice on top of the jar and watch what happens
-After you start to see water droplets at the top of the jar drip down, open the lid and watch what happens
What is Happening:
The hot water in the jar is evaporating into water vapor and collecting at the top of the jar. Warm air rises and the water vapor droplets are so light they rise to the top. At the top of the jar, those water vapor droplets meet cold air from the ice in the bowl. That cold causes some of the water vapor to condense back into liquid water. Those are the beads of water to watch for at the top of the jar! This is the part we’ve done before; you can click here to watch the video of our first time doing this! Or you can click here to see more about the water cycle and how water changes phases from solid to liquid to gas.
This time we added hairspray to this experiment which becomes a “condensation nucleus” – a tiny particle for those water vapor droplets to collect on when they transition back to liquid. In the atmosphere dust, dirt, aerosols, pollutants, and any other airborne particle can become a condensation nucleus. These tiny particles give the water something to collect on as a cloud is forming. For our experiment today, it will make our cloud a little easier to see at it floats out of the jar. It’s a microscopic difference, but the droplets making up our cloud are a tiny bit bigger (so a bit easier to see) when we add the hairspray particles for them to collect on.