Three main elements must be present in order for clouds to form:
• Moisture
• Cooling temperature
Condensation nuclei

Create a Portable Cloud!

The purpose of this experiment is to observe how moisture, cooling temperature, and condensation nuclei play a role in cloud formation.

Gallon jar

Food coloring

Hot and cold water

Matches

Rubber glove

Rubber band

Lamp

1. Pour 100 ml of cold water into the jar. Add food coloring to the water.

2. Swirl the water in the jar for one minute to allow some water to evaporate.

3. Stretch the open end of a rubber glove over the mouth of the jar, with the glove fingers hanging down into the jar.

4. Place a rubber band around the mouth of the jar to secure the glove.

5. Turn on the lamp so it shines through the jar.

6. Insert your hand into the glove. Pull quickly outward without disturbing the jar's seal. Record your observations.

7. Quickly push your hand back down into the jar. Record your observations.

8. Carefully remove the glove from the jar.

9. Drop a lit match into the jar and quickly seal it again with the rubber glove as before.

10. Insert your hand into the glove. Pull quickly outward without disturbing the jar's seal. Record your observations.

11. Repeat the entire procedure using hot tap water instead of cold water.

What do you see happening inside the jar?

Water vapor is created as water heats under the lamp. Swirling the water also help water molecules to move into the air from the water’s surface.

When you pull the glove out of the jar, the air pressure is lowered inside the jar. The jar contains the same number of air molecules, but they have more space between them (they are less dense). Molecules collide with each other less frequently and slow down, causing the air temperature to go down.

When you press the rubber glove into the jar, you are increasing the air pressure. The air becomes more dense as the molecules are crowded together. This also causes the air to heat up as molecules collide with each other more often.

The smoke particles provide tiny nuclei on which water vapor molecules condense, when the air temperature cools. This forms a little cloud.

There must be three main ingredients present in order for clouds to form:

• Moisture - There must be sufficient water vapor in the air to build a cloud.

• Cooling air - The air temperature must decrease enough for water vapor to condense.

• Condensation nuclei - Tiny particles, invisible to the human eye, such as dust, dirt, and pollutants, provide surfaces on which water molecules can gather and condense into water droplets.