In this experiment we will make a cloud in a bottle. Clouds form when water vapor cools down. Warm moist air in the atmosphere rises and the pressure reduces as it goes higher. As pressure reduces it gets colder. Eventually the water vapor cools enough to form clouds.
Materials - Clean Clear 1 Liter Plastic Bottle - Bicycle Pump with Ball Inflater Stem Needle - Matches - Watches - Wine Bottle Cork or Rubber Stopper - Some Duct Tape - Water - Rubbing Alcohol
Watch Video: Make A Cloud in A Bottle
Process To Make A Cloud In A Bottle:
- Cut a wine bottle cork about 1/2 or so and stick the bike pump ball inflater needle all the way through so it sticks out the other end. Test the cork in your plastic bottle mouth to make sure it makes a good seal. If you need it add a couple wraps of duct tape around the cork so it fits in the mouth of the plastic bottle, but provides a good seal. Then attach the inflater stem to your bike pump.
- Fill the bottom of the plastic bottle with warm water. Only use enough warm water to cover the bottom don't over-fill.
- Add smoke particles to the bottle. To do this light a match and let is catch fire for two or three seconds.
- Give the match a gentle blow and extinguish the flame. Then quickly hold the match inside the bottle letting as much smoke as possible inside the bottle.
- Stick the wine cork inflater stem assembly into the mouth of the plastic bottle. Start pumping air inside. Give it a good 20 pumps or so to increase the air pressure inside the bottle. The smoke should disappear as the pressure increases.
- Pull the cork out of the bottle. And wham! You have made an instant cloud in a bottle.
- For a bigger more visible cloud try this. Dump the water out. Replace the water with in the bottom of the bottle with a little rubbing alcohol. Shake the bottle to ensure the rubbing alcohol covers all the walls inside the bottle. DO NOT USE THE MATCH AND SMOKE as you did previously! Fit your cork or stopper with bike pump needle back onto top of bottle. Give it a good 20 pumps (hold cork on bottle with your hand). Then pull off the cork or stopper.
The Science Behind Cloud In A Bottle: Invisible water molecules are always present in the air that surrounds us. That is what we call water vapor. As they linger around in the earths atmosphere the do not normally stick to other particles also in the air.
Pumping air inside the bottle compresses the molecules. When we pull the cork out, we are permitting the air molecules to expand. When the air molecules expand their temperature lowers and they get colder. As they cool, the molecules start sticking together (water vapor, air molecules and smoke particles). This combination allows small water drops to form. Just like the clouds in the sky. Except water vapor in the sky finds pollution and other particles to stick on.