Have you ever wondered how clouds form? In this activity, you can make your own cloud to see for yourself!
Clouds form from the condensation or freezing of water vapor. Condensation is the process of a gas changing into a liquid. In this activity, the gas is water vapor and the liquid is the cloud you create. When water vapor cools, it turns into a liquid – or condenses – onto a surface.
For example, take a cold water bottle outside on a warm day. You will notice that water droplets form on the outside of the bottle. These droplets are water vapor from the atmosphere condensing on the surface of the bottle. They do this because the surrounding air cools when it touches the bottle. Clouds form the same way. Water vapor in the atmosphere cools and condenses on particles in the air, creating a cloud.
Follow the steps below to create your own cloud and see this process in action!
Materials
1. Form the water vapor
Fill a jar with 2 inches (5 cm) of warm water and stir. The warm water will form water vapor through a process called evaporation. Evaporation is the process of liquid changing into gas. The water vapor will begin to rise inside the jar. You will not be able to see the water vapor. It is an invisible gas.
2. Form smoke particles
Ask an adult to light a match, blow it out and quickly drop it into the jar. The smoke particles will provide a surface for the water to condense on.
3. Cool it
Immediately place an ice-filled metal tray or hard-plastic frozen ice pack on top of the jar.
4. Watch the cloud appear
Observe the inside of the jar carefully. A misty cloud should appear near the top of the jar. Why does this happen? The warm water vapor mixes with air and smoke particles. It rises inside the jar and then cools when it comes near the tray of ice. As the water vapor cools, it condenses into very tiny droplets on the smoke particles. When enough condensation occurs, we see it as a cloud. If you have a hard time seeing the cloud, slightly lift the metal tray or ice pack from one side of the jar and look for wisps of cloud escaping the jar.
5. Make it disappear
Remove the metal tray or ice pack. What happens? The cloud disappears. Why? As the cold cloud warms up, the condensed water droplets evaporate once again and turn into water vapor.
6. The real deal
This exact process occurs naturally in our environment. The particles aren’t always from smoke. They can be particles of various materials, including dust and pollution. Evaporated water condenses to form clouds. These clouds may later produce rain or snow, which is commonly called precipitation. Together, evaporation, condensation and precipitation play an important role in the water cycle.
