Monday, December 20, 2010
salt and ice
I asked her, "Why do YOU think we spread salt on an icy sidewalk? Can you guess?"
She guessed, "The salt melts the ice?"
We decided to see if this were true. I said, "We'll see if ice added to water makes it harder for the water to freeze."
I explained (after quickly Googling this to make sure I didn't spread misinformation) that salt speeds up the melting of the ice because it can make ice melt at a lower temperature. Salt also helps keep the ice from re-freezing.....which we saw when we put the salt water in the freezer!
I later came across an experiment where kids can use salt to "glue" an ice cube to a string, and then lift it up. This is exactly the sort of thing that sets my geek heart aflutter.
(I may be a geek, but I'm not a science whiz, so preschool science experiments may be as good as it gets for me. I plan to enjoy this while it lasts, and before I become unable to comprehend any of it.)