The Basic Properties of Water

What is the water cycle? The water cycle describes the existence and movement of water on, in, and above the earth. The water cycle has no starting point, but it is in the oceans where most of Earth’s water exists. Even though the balance of water on Earth stays fairly constant, individual water molecules can come and go at will. The water in your juicy apple may have fallen as rain on the other side of the world six months ago, or it could have been used millions of years ago by the dinosaurs.

Some of it evaporates as vapor. Ice and snow can convert directly into water vapor. Rising air currents take the vapor up into the atmosphere along with water transpired from plants. The vapor rises into the air where cooler temperatures cause it to condense into clouds. These clouds then collide with other cloud particles and precipitation (rain or snow) falls. The snow can accumulate as ice packs or glaciers which can store frozen water for thousands of years.

After a long, long drought rain is very welcome indeed What is rain? The dictionary defines it as a form of precipitation, other forms of which include snow, sleet, hail and dew. Not all rain reaches the earth. Some evaporates while falling through dry air. This phenomenon often happens in hot, dry deserts.

Do you believe that raindrops are teardrop shaped? This is not true. Only water dripping from taps are teardrop shaped. Raindrops are mostly shaped like squashed hamburger buns or doughnuts. It is said that rain is heavier immediately after a flash of lightning. This is to do with the electric and magnetic field generated by the lightning.

Cloud seeding is a subject that has been greatly discussed in the papers. Many people believe that cloud seeding will break the drought. Aircraft or rockets shoot silver iodide (dry ice) into cloud. This encourages water vapor which then falls as rain. There is quite a controversy as to whether this really works.

Most precipitation falls into the oceans or on land, where the water flows off as surface runoff into rivers and streams. Some of the ground water seepage accumulates as freshwater lakes. All of this water keeps moving and finds its way back to the oceans where the cycle begins again.

This same water cycle has been working since time was. All living things depend on this cycle, because without it we would cease to exist. The water cycle has no beginning and no end. It keeps going round and round.