Cloud in a bottle Step 3: stop squeezing the bottle which results in a decrease in temperature and condensation results in cloud formation
A simple experiment which demonstrates the effect of smoke particles as nucleation centres causing condensation.
Step1:
A small quantity of smoke is added from a smoking wooden splint or a smoking match to a plastic bottle partially filled with water.
Step 2:
This is a reversible process. When the plastic bottle is squeezed there is an increase in pressure causing a rise in temperature. No condensation is visible.
Step 3:
Stop squeezing the bottle. As you let go the bottle the air expands and cools down. As the temperature is lowered condensation occurs producing a cloud in the bottle.
Step 4:
Repeatedly and quickly then squeeze to make the cloud disappear (evaporation) and stop squeezing to get the cloud to reappear (condensation).
Without the smoke particles no cloud appears! In the Earth's atmosphere cloud formation can result when there is tiny dust particles e.g. from volcanic erruptions or man-made particles such as silver iodide during cloud seeding.
Could formation may form which would not otherwise not occur if such particles were not present. The moisture content, air pressure and temperature still have to be at optimum values for condensation to occur to cause cloud formation and even rain! The optimum conditions required for cloud seeding in the Earth's atmosphere are are still controversial!
Cloud in a bottle Step 3: stop squeezing the bottle which results in a decrease in temperature and condensation results in cloud formation
A simple experiment which demonstrates the effect of smoke particles as nucleation centres causing condensation.
Step1:
A small quantity of smoke is added from a smoking wooden splint or a smoking match to a plastic bottle partially filled with water.
Step 2:
This is a reversible process. When the plastic bottle is squeezed there is an increase in pressure causing a rise in temperature. No condensation is visible.
Step 3:
Stop squeezing the bottle. As you let go the bottle the air expands and cools down. As the temperature is lowered condensation occurs producing a cloud in the bottle.
Step 4:
Repeatedly and quickly then squeeze to make the cloud disappear (evaporation) and stop squeezing to get the cloud to reappear (condensation).
Without the smoke particles no cloud appears! In the Earth's atmosphere cloud formation can result when there is tiny dust particles e.g. from volcanic erruptions or man-made particles such as silver iodide during cloud seeding.
Could formation may form which would not otherwise not occur if such particles were not present. The moisture content, air pressure and temperature still have to be at optimum values for condensation to occur to cause cloud formation and even rain! The optimum conditions required for cloud seeding in the Earth's atmosphere are are still controversial!