Sea Activities

Pedro Rodriguez                Bateman School
4634 S. Homan Ave              4220 N. Richmond St
Chicago IL  60632              Chicago IL  60618
(312) 247-4754                 (312) 534-5055

Objectives:

     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.

Materials Needed:

*Group students in 4 or 6
*Mural paper, light blue, cut paper 5 foot long
*Crayons
*Sea creatures stencils
*Pencils

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. 

Materials Needed:
  
*Masking tape
*Small plastic bowl
*Plastic bags large enough to hold the bowl
*Sea salt
*Tap water
*Plastic spoons
 
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. 

Results:

     Have the students taste the liquid collected.  The liquid inside the 
plastic bag will taste like fresh water. 

Materials Needed:

*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
*Fresh water

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. 

Results:

     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. 

Materials Needed:

*Fresh water
*Sea salt
*Test tube or plastic clear glass
*Medicine dropper
*Silver nitrate

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. 

Results:

     The silver nitrate will react with the sea water and will turn milkly white 
if chloride ions are present in the sea water. 

Performance Assessment:

Students should be able to:

*Answer oral questions.
*Observe the changes taking place in the experiments.