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Water Evaporation and Condensation

Water is constantly on the move, whether in the oceans and rivers, in a pond that looks completely still, or in a glass of water. Water molecules move about at different speeds all the time. If they move fast enough, some break away from the surface and enter the air. This is called evaporation. Some of the molecules then fall back into the water. But others become water vapor and are carried away by air currents. In this way some of the water is gradually lost to the atmosphere.
You can see this happen if you leave a saucer of water uncovered indoors. After a time, there will be no water left. It will all have evaporated.
Wet laundry on a clothesline dries more quickly in a breeze. The wind carries away the water molecules soon after they enter the air from the washing. Hardly any of them fall back on the clothes.

When water is heated, all of its molecules speed up and more of them escape. If water is made hot enough, all the molecules eventually escape and the water boils away. All of it becomes water vapor.
Heat speeds up evaporation. Cold slows it down and may even stop it, turning the water vapor back into water droplets. This process is called condensation. When you take a hot bath, molecules from the bathwater escape into the air and become water vapor. Some of them touch the cold bathroom walls and windows, and this cools them down and turns them back into drops of water. The walls, windows and the bathroom mirror become misty.
The insides of windows sometimes become misty on rainy days for the same reason. Inside a warm room, molecules of water vapor are moving about. Some of them meet the glass of the windows, which the rain has cooled. The loss of heat turns the water vapor near the glass back into water. If it gets cold enough at night, the water on the window will freeze and you may wake up to find your windows are frosty on the inside.
These wet clothes will dry faster when the wind is blowing. The water molecules evaporate into the air, and are blown away by the wind.
When water is cold, very few molecules will evaporate.
When water is warmed, the water molecules will escape more quickly from the surface into the air.

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