Condensation

• Go outside on a cold (usually less than 50 degrees Fahrenheit), damp day. Take a deep breath and then breathe out from your mouth slowly. As you breathe out the warm water, vapor in the air from your lungs immediately condenses as it hits the cold air. Tiny water droplets form giving the effect of a cloud. This is because the water vapor cools rapidly and attach to minute particles of dust in the air. When this happens the water vapor becomes visible to the eye, the same as happens when real clouds form.
  
  

Steam

• You can do a simple experiment about clouds using your shower. Turn the shower to the hottest setting and turn on the water, then close the shower door and watch from outside the shower. The water vapor from the hot water fills the cubicle with steam and effectively makes a cloud. The cloud is thickest near the top of the shower while at the bottom there isn’t a cloud. Look at the shower door and you see water droplets getting larger. As they increase in size, they drip down the door.
  
  

Temperature

• Conduct an experiment about clouds by putting five or six ice cubes in an aluminum tray and put the tray containing the ice cubes into the freezer. Put about 1 inch of hot water into a glass bowl. Get the tray from the freezer and place it on top of the glass bowl so the bowl is covered. Look through the side of the bowl and you see a cloud forming near the top of the bowl. The water vapor from the hot water rises upward until it gets near the cold tray. The vapor then condenses and forms a cloud. Keep watching and you see water droplets forming on the underside of the tray and falling back into the hot water, just like rain.
  
  

Air Pressure

• The higher water vapor rises, the more it cools and therefore the larger and thicker the cloud. High air pressure pushing downward restricts the vapor from rising too high and therefore clouds are unable to form. Low air pressure lets the vapor rise up high and clouds form. Do an experiment about how air pressure affects cloud formation by pouring water into a plastic bottle so it’s about one-quarter full. Squeeze the bottle to get the air out and then light a match and put it near to the neck of the bottle. Blow out the match and let release the pressure on the bottle so it sucks air and the smoke from the match into the bottle. Put the cap on tightly and watch the smoke the swirling around like a cloud. Squeeze the bottle hard and the smoke disappears. Let go and the smoke returns. Squeezing the bottle increases air pressure and vaporizes the smoke molecules; as soon as you stop squeezing the bottle, the pressure falls and the molecules are visible.