Wednesday, January 13, 2010

We are scientists! Salt and the freezing point.

We used the scientific method to answer some questions about why oceans don't freeze and why we put salt on icy roads.
The kids learned about the control in an experiment and the variable. The control was a cup of fresh water and the variable was a cup of water in which we added salt. Those cups went in the freezer to see the effects, if any.

While we waited for the cups of water / salt water to do their thing we looked at what salt would do to an ice cube. It was pretty evident to the girls why we add salt to roadways and walkways. I tried to see if they could make some inferences, after this observation regarding the cups in the freezer but they needed some help coming to the conclusion that salt lowers the freezing point. Not quite sure if they "get it" even now but it left them excited anyway!

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