Water Cycle - Marcom Projects

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Script
You see, every molecule of water has what is called kinetic energy. This kinetic
energy makes the molecules vibrate. Heat from the Sun can increase the kinetic
energy, and make the molecules vibrate faster. As they move faster, they spread
out. The molecules with the most energy escape their bonds with the slower
moving water molecules, and are absorbed into the air as gas, or water vapor.
The rate of evaporation is determined by the temperature and humidity level
of the air. If the air is hot and dry, water will evaporate more quickly. If the air
is cool and damp, evaporation is slow.
Once the water vapor rises into the air, it reacts to atmospheric conditions.
You see, our atmosphere can hold a certain amount of water vapor at a given
temperature. The higher the temperature, the more water the atmosphere can
hold. If the temperature cools, the kinetic energy in the water molecules slows
down. The water vapor bonds together again and forms liquid droplets around
dust particles in the air. This phase is called condensation.
If the water vapor is close to the earth’s surface when it condenses, it forms fog.
If this takes place higher in the atmosphere, the condensation forms clouds. The
liquid water molecules hover in cloud formations, until the atmospheric conditions
change. Wind currents move the droplets around, becoming bigger and heavier.
When the condensed water droplets become too heavy, they fall to Earth as
precipitation, or rain.
Of course, precipitation can take in many forms, depending on the weather
conditions. Snow, sleet and hail are all icy forms of precipitation. Mist and
haze are lighter forms. Did you know that an estimated 4.2 billion gallons
of precipitation fall on Earth every year? That’s a lot of water!
Once the water has reached Earth again, it has completed the water cycle,
and is ready to be evaporated back into the atmosphere. But water isn’t always
evaporated as soon as it reaches the ground. Believe it or not, water has more
interesting travels on and below Earth’s surface. But before we venture through
water’s travels, let’s take a quiz break.
Now that you’ve got the basics, a few of my friends are stopping by to quiz
you on what you’ve learned so far. Enjoy!
Water Cycle Video Quiz © Sunburst Visual Media, a division of Global Video, LLC