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Chemistry > Salt > How Much Salt Does It Take To Make An Object Float?
 

Site: http://collaboratory.nunet.net/timber/scifair/kindto4/16.htm

Grade Category: Elementary

Subject Category: Chemistry

Sub Category: Salt

How Much Salt Does It Take to Make an Object Float?
by Joe G. and Nat Z.

*Hypothesis * Purpose * Materials * Procedure * Results * Conclusion * Bibliography & Links * 

 

Hypothesis 


 It will take 14 tsp of salt to make a rock float. It will take 10 tsp to make the  4 marbles float . It will take 12 tsp of salt to make  the apple float.It will take the kiwi 9 tsp. of salt to float.  It will take 9 tsp. for the egg to float.  It will take 11 tsp. for the paper clip to float.  It will take 10 tsp for the eraser to float. The weight and smallness of the objects determines how much salt it takes to make them float.

Purpose 


We did this experiment to find out how much salt it takes to make some things float.  We got interested in this topic because Natís Dad got a postcard from a friend who had visited the Dead Sea.

Materials   

  • salt, 
  • teaspoon,
  • measuring cup
  • 7 bowls, 
  • water, 
  • rock, ,
  • 4  marbles,
  • apple, 
  • kiwi, 
  • egg,
  • eraser, 
  • paper clip

Procedure   


 First you fill the bowls with  2 cups of water.  Add one teaspoon of salt at a time. Count to see how many teaspoons of salt it takes to make each item float.

Results   


Apple floated in unsalted water. Kiwi floated in 6 tsp. of salt. Egg floated in 8 tsp.of salt.  Paper clip, eraser, marbles, and rock still did not float after 15 tsp. of salt.  We stopped at 15 tsp. because the salt stopped dissolving. 

Conclusion 


We figured out that the density of the objects determined how much salt it would take for the objects to float or whether they would float at all.  Adding salt to the water makes the water more dense. An object floats when the water is denser than the object.

Bibliography & Links   

  • Ardley,Neil, Working with Water ( Franklin Watts,1983)
  •  Burt, Olive, The First Book of Salt (Franklin Watts, 1965) 
  •  Goldin, Augusta, Salt (Crowell Company, 1965) 
  •  Vander Boom, Mae, Miracle Salt  (Prentice- Hall, 1965) 
  •  Kraske, Robert, Crystals of Life  ( Doubleday,1968)

 

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