Last week we were sick around here, so we didn't get to do any science experiments, so this week we did a twofer (two "fer" the price of one). Ian had a unit in his science text book on Oceans with a suggestion on how to demonstrate why the ocean is salty but rain is not.
Step one: Mix 4 tablespoons of salt into one cup of water and stir until as much salt as possible is dissolved.
Step two: pour the saltwater into a pan and heat to boiling (this is the evaporation step)
Result: the water boils away (evaporates) and leaves the salt behind.
For the second part of the demonstration, we put some ice packs into a cake pan and waited until the pan was really cold - this was to simulate the cooler air high in the atmosphere. Then my lovely assistant held the pan into the steam above the boiling (evaporating) saltwater. Almost instantly the steam condensed on the bottom of the cake pan and "raindrops" formed. When we tasted the raindrops they were not salty at all.
Happy science, everyone!
PS - We are leaving on a vacation later this afternoon, so I won't be posting for a couple of weeks. I hope you all have a lovely spring.
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