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Pedro Rodriguez Bateman School
4220 N. Richmond St
Chicago IL 60618
This lesson has been designed for the bilingual kindergarten learner, but
can be used for other grade levels 1st to 3rd.
*The students will recognize sea creatures.
*The students will learn that the sea water is salty, how to extract salt, and
convert seawater into fresh drinking water.
*The students will learn that there are bodies of sea water where the amount of
salt is so great that people float effortlessly in them.
*The students will learn and recognize that sea water has chloride ions.
*Group students in 4 or 6
*Mural paper, light blue, cut paper 5 foot long
*Sea creatures stencils
Strategy: Setting the stage
Setting the stage in your classroom to create a sea atmosphere. Have the
students draw and create the ocean using the sea creatures stencils. After the
students have finished, hang the murals created by students around your
classroom. This will prepare a learning atmosphere for the student to learn
about sea creatures and seawater.
*Small plastic bowl
*Plastic bags large enough to hold the bowl
Strategy: Fresh Water from Sea Water
The light from the sun passes though the clear plastic and heats the
surface of the salty water in the bowl. Although it is a simple process,
extracting fresh water from sea water on a large scale is very costly. Sea
water is first heated then the steam is boiled off and condensed into fresh
water leaving the salt. Group the students in 4 or 6. Have the students cover
the bottom of the bowl with a thin layer of sea salt. Fill the bowl one-half
full with tap water and stir until all the salt is dissolved. Set the bowl
inside the plastic bag and close the opening with masking tape and place the bag
in direct sunlight. After 24 hours open the bag and collect the liquid around
the inside of the plastic bag with a plastic spoon.
Have the students taste the liquid collected. The liquid inside the
plastic bag will taste like fresh water.
*Group students in 4 or 6
*2 Large glass containers or breakers
*Sea salt, making sea water use 35 grams of salt in 965 grams of fresh water
*2 hard boil eggs
Strategy: Making a egg float
To demonstrate how salt content is measured by the buoyancy force, as the
salt content of the water increases. The water gets more dense and has greater
buoyancy force, and the fresh water is less dense, and has less buoyancy force.
Float an egg in salt water. After you have made sea water, fill two glasses,
one with fresh water, the other one with sea water. Place an egg in each one of
the glasses. Describe the results to the students.
The egg will rise and float in the sea water and the egg in the fresh
water will sink to the bottom of the glass. This is the result of the buoyancy
force, the density of the water increases.
*Test tube or plastic clear glass
Strategy: Testing for the Chloride Ion
This is a simple chemical experiment which can be easily done to test sea
water for the chloride ion. Pour 25 to 30 milliliters of water into a test tube
or a plastic cup. Add a few grams (three or four) of sea water. Shake to
dissolve the salt. Cautiously add two to three drop of silver nitrate do not
shake or stir.
The silver nitrate will react with the sea water and will turn milkly white
if chloride ions are present in the sea water.
Students should be able to:
*Answer oral questions.
*Observe the changes taking place in the experiments.