As we continue in our study of weather, we started learning and talking about clouds! After sharing what we already know about clouds, we dug a little deeper and talked about how clouds are formed. We were all familiar with water vapor going up into the air but talked more in depth about what exactly happens next!
As the vapor goes up, it cools off. However, the cool air cannot hold as much water vapor as warm air so the vapor condenses on tiny pieces of dust or pollution that are floating in the air and forms tiny droplets of water. Where there are enough droplets, a cloud is formed! The clouds we see are made up of millions of tiny droplets! That means a cloud can weigh more than an airplane!
To bring this idea to life, we created our own cloud in the classroom! We started off by adding a couple inches of hot water to our jar to form our water vapor. We placed a bowl on top of the jar and filled it with ice cubes and let it sit for about 20-30 seconds. This allowed the water vapor to cool off. The bowl was quickly removed and hairspray was sprayed inside the jar. The bowl of ice was then placed back on top. We got down on eye level and saw the cloud begin to form!!! The video below shows the bowl being removed and the cloud coming out of the jar!
The Science Behind Our Experiment: For clouds to form, they need 3 things: cool air, water vapor, and condensation nuclei. An example of this nuclei would be tiny particles of dust, pollution, salt, or smoke. Water vapor evaporates from the surface. As it rises, the air cools down. The cooler air high in the atmosphere cannot hold as much water as the warmer air close to the Earth’s surface. The water vapor will want to condense, but for it to change from a gas to a liquid, the water needs a non-gaseous surface. Cloud condensation nuclei provide that surface. In real life, this is usually salt from the ocean, dust, or pollution. For this experiment, that was represented with the hairspray.
