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5th - Water Cycle - Science S.G. (01-08-10)

Quest scheduled for Friday, January 15, 2010.
STUDY
PLAY
precipitation
when water droplets collide and merge, rain, sleet, snow, or hails falls
surface runoff
water that does not soak into soil moves toward oceans, lakes, rivers, and streams
infiltration
when water falls to Earth as precipitation, it soaks into the soil; this is when groundwater flows.
clouds
are made of water droplets and ice crystals, depending on the temperature
sun
heat from the sun warms water from oceans, lakes, rivers, and streams
transpiration
plants and trees take in water through their roots. Some of it passes out through the pores in their leaves and evaporates into the air.
condensation
when water vapor rises and cools, it becomes water droplets
evaporation
heated water turns into vapor and rises
What makes the Water cycle work?
changes in temperature make the cycle work
fresh water
only 3% of the water is nonsalty; it is constantly recycled during the water cycle and can be a solid, liquid or gas
2/3 of the Earth's surface
is covered by water
95 of the Earth's water7
is salty and undrinkable ocean water
Life of a Raindrop - Step 1 - Evaporation & Transpiration
this occurs when the sun heats water on oceans, lakes, and rivers; then the water molecules rise into the air as an invisible gas called water vapor
Life of a Raindrop - Step 2 - Condensation
As water vapor rises, it cools. When the air temperature is cool enough, vapor condenses into droplets. Water droplets form around microscopic bits of dust and salt in the air. Clouds are made up of millions of tiny water droplets with dust specks inside. The darker the cloud, the more water it has.
Life of a Raindrop - Step 3 - Precipitation
The droplets are still too small to fall. The droplets blow up and down in a cloud. they combine with other droplets and become raindrops, and are now too heavy to stay in the cloud. Gravity sends them plunging to Earth at at average speed of 14 miles per hour.

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