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Knows that clouds, like fog and steam from a kettle, are made of tiny droplets of water.

Making Clouds: Aerosol-Cloud Interactions in a Beaker

This example discusses the process of cloud formation and the ability of cloud droplets to scatter light. A demonstration \r\nthat creates a cloud in a beaker is described.

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Why Don't Clouds Fall Out of the Sky?

All of you have seen big, puffy clouds "floating" in the sky on a summer's day. Why do clouds stay in the sky? Why don't they fall down? Maybe clouds "float" for the same reason that helium balloons float. Maybe they are lighter than air. That can't be true because we know that clouds are made of water. Water is not lighter than air - water does not float. So why don't clouds fall out of the sky? The two biggest reasons that clouds stay in the sky are 1) small drops, and 2) wind. Small drops of water fall more slowly than big drops.

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