The Dead Sea borders Israel, the West Bank and Jordan. It is more than 400 meters below seal level and is the lowest point on dry land. It is over 1/3 salt, and this hypersaline water makes floating easy.
I love science and thought this fun experiment would be a great way to teach some scientific principles to my preschooler, as well as learn about the Dead Sea.
I first filled three glasses (because working with a 3-year old, I needed an extra, haha) with warm water (dissolves salt easier). The first glass we designated our control glass and remained tap water. The second we called our experimental glass and filled it with our variable, 1/3 cup salt (trying to get close to the 33% salt concentration).
We stirred it thoroughly to make sure the salt had dissolved.
We used cherry tomatoes to demonstrate buoyancy. I thought they were a fun holiday color, but you can use lots of different objects. Just remember that you’ll need an object that doesn’t naturally float and one that isn’t too heavy (I initially tried a small figurine and that didn’t work).
We discussed how the addition of solutes increased the density of the solvent (water), allowing the cherry tomatoes to float.
This activity was a hit – my daughter loved removing the tomatoes and dropping them back in. The water ones sunk immediately, our “Dead Sea” ones floated perfectly.
Someday I hope to float on the Dead Sea myself… Someday. 🙂
- Control – a group or individual used as a standard of comparison for checking the results of a survey or experiment.
- Experimental – a group or individual exposed to the variable(s) being studied.
- Variable – an element, feature, or factor that is liable to vary or change.
- Density – degree of consistency measured by the quantity of mass per unit volume.
- Buoyancy – the ability or tendency to float in water or air or some other fluid.
- Solute – the minor component in a solution, dissolved in the solvent.
- Solvent – the liquid in which a solute is dissolved to form a solution.
- Dissolve – become or cause to become incorporated into a liquid so as to form a solution.