The water cycle

• Evaporation - Water turns from a liquid to a gas when it evaporates. Energy from the Sun can evaporate water from all places on the Earth’s surface such as puddles, ponds, lakes and oceans.
• Condensation - After evaporation water can cool and convert from gas to liquid, often forming clouds.
• Transport - Water within clouds can be blown many miles by strong winds and so transported to other areas.
• Precipitation - Precipitation occurs when rain, snow, hail and sleet fall from the sky.
• Surface runoff - Much water will be absorbed into the ground after precipitation but if a large volume falls or the ground is already wet some water can run along the surface of the ground.
• Infiltration - This occurs when water that has fallen as precipitation is absorbed into the ground. This can then be stored within underground rocks called aquifers.
• Transpiration - Plants need to maintain a constant stream of water to their leaves for transport and support. So they allow some water to evaporate as water vapour from their leaves to mean that more is continually ‘pulled’ to their leaves from the soil.
• Water cycle

  1. Evaporation from oceans

  2. Water vapor travels into air

  3. Water vapor condenses to form clouds

  4. Precipitation (rain, snow, hail, sleet)

  5. Water hits ground

  6. Some evaporates back into atmosphere

  7. Some passes through rocks to form aquifers

  8. Some forms rivers/streams

  9. Rivers/streams drain back into sea
• Almost all water on Earth is found in the oceans and is salt water
• Energy from the Sun causes the water to evaporate from the surface of the sea
• Precipitation contains fresh water (does not contain salt)
• Transpiration

  Plants take up water in roots, water moves up plant in xylem and passes out of leaf stomata as water vapor
• Animals take in water

  Through drinking and in their food
• Animals release water

  In their urine and feces, and when they exhale