SMMART SCIENCE I : GROW YOUR OWN SNOWMAN
Even if there isn't any snow outside in your front yard...we're making our own snow fun!
Salt Crystal Snowmen can glisten anytime of year! You can use normal table salt (NaCl) for this activity.
You will need:
An adult to help with this
Cardboard tube from kitchen roll or toilet roll
Felt tip pen
Shallow dish or saucer
1. Draw a snowman outline on one side of the cardboard tube. (If using a kitchen roll tube cut it in half first so that it’s shorter - after all, who makes a tall thin snowman?) *I let my daughter decorate the snowman with markers
2. Cut around the outline of the top of the snowman making sure that you leave a thin circle of cardboard at the base of the tube. i.e. leave the base intact so that the snowman is supported but from the front you should see a snowman shape. (Be careful when using scissors)
3. Pour 100ml of warm water into a cup. (A tablespoon is about 15ml)
4. Add a teaspoonful of salt and stir till dissolved. *Let your child check the line of the measuring cup to see if you have enough warm water and allow her to dump in the salt and stir.
5. Continue adding salt in this way until no more will dissolve and you have some salt left at the bottom of the cup. This is known as a saturated solution.
6. Pour the solution into a shallow dish or saucer and stand the snowman in it.
7. The solution should slowly start to rise up the cardboard. Now leave the whole set-up in a safe place for a few days.
What's happening? The salt is dissolved in the water to form a saturated solution. As this solution starts to travel up the cardboard snowman the water evaporates leaving behind salt crystals. In time your snowman will look as if he is glistening! As more salt solution travels through the cardboard it allows the small salt crystals to grow even bigger.
(This activity is taken verbatim from: http://www.planet-science.com/newsletters/randomised/22/index.html#4)
*I have also had success from boiling 1 cup of water and adding 1/4 cup of salt, stirring, and perhaps adding a little extra salt until the solution is super saturated. Boiling water (heat) helps to break the salt's ionic bonds and dissolve the salt into solution.