Water is our most common natural resource.
It is essential to the biology and chemistry of all living things, it plays
a major role in shaping the earth and is an active agent in many physical
reactions. It is important to most life to keep it clean. There
is plenty of water on Earth, but 97% of this water is saline (contains
dissolved salts). Only 3% is fresh and about two thirds of that amount
is locked up in polar ice caps and glaciers; about one third (1%)
can be found as ground water, lakes, and in the atmosphere.
Water exists in three states of matter including solid (ice), liquid (water), and gas (vapor) at normal conditions.
Water is a colorless, odorless, tasteless liquid with a melting point of
zero degrees centigrade and a boiling point of 100 degrees centigrade.
Water is cleaned as it passes through nature’s
water cycle. When water evaporates to the gaseous phase, it leaves
the dissolved impurities behind. Water can also be cleaned through
other natural ways. Overtime, civilization have developed ways in
which they can also clean water by taking advantage of part of the natural
- Water is important to our
lives. Discuss with your students some of the reasons why water is
necessary to humans and then write these reasons on the board. Hopefully,
your students should come up with the following reasons: drinking,
for travel, watering plants, and for cleaning. Discuss the properties
of water with your students.
- It is important that you review how
the water cycle functions. After you review, see if the students
can derive the cycle by themselves by using the worksheet.
Have the students generate a cycle on the board by having each student
add a component to the cycle until the entire water cycle is drawn on the
- Use the following definitions to help
students create a water cycle using the worksheet.
- evaporation - the changing of liquid to water
- condensation - the changing of water vapor
to a liquid
- cloud - a visible mass of particles of
water or ice in the form of fog, mist, or haze, suspended at a considerable height in the air
- precipitation - forms of water vapor
that are heavy enough to fall to the Earth's surface such as rain, snow,
sleet, hail, and fog
- infiltration - the process by which water seeps
into the soil and become groundwater
- spring - a source of water from the ground
- marsh - a parcel of soft wet land, that can be
either salt or fresh water
- artisan water - underground water trapped
under pressure in a porous layer between non-porous rock layers
- water table - the level below which the ground
is saturated with water
- lake - a body of water larger than a pond and
too deep in parts for rooted plants to live
- river - a natural stream of water larger
than a creek and emptying into an ocean, lake, or another river
- ocean - the bodies of salt water that
cover nearly three fourths of the surface of the Earth
- groundwater - water found below the surface
of the Earth
- runoff - water that flows on the surface
or through the ground into streams, rivers, lakes and oceans
- transpiration - the evaporation of water from
the leaves of plants