Icy Fun

These activities all involve ice and color to help cool down the last few days of summer.

Some green ice.

Mixing Colors (for young children)

• food coloring
• water
• ice trays (or small containers to freeze the water in)
• bowls/cups (preferably light colored or clear)

You need to make ice cubes in several different colors. To this, first add a few drops of food coloring to some water, mix it, then pour it in the ice tray and freeze it. I assume if you don't mix it, the food coloring won't be evenly distributed, but I haven't actually tried. That might be another experiment you can tie in - seeing how the ice looks when the food coloring wasn't mixed. Have at least the primary colors, but use more if you want!

Then pair up different colors in different bowls. As the ice cubes melt, the colors will start to mix. See if the kids can guess ahead of time which colors will form. Once you've done it with just pairs of colors, try it with three different colored ice cubes.

Rainbow Tunnels

• food coloring (or other form of liquid color)
• salt
• water
• large-ish containers

Freeze several BIG ice cubes using the large containers. If you want your ice cubes to have more interesting shapes, you can fill a balloon or plastic baggie with water and freeze that. You will probably have to leave them overnight. When you actually want to start the activity, do it outside or in a large box - somewhere you won't mind things getting all wet.

Image from artsandcreativity.blogspot.com

 In several small dishes, put a bit of water, salt and food coloring. Set yourself up with a nice variety of colors. Now the fun begins! Start pouring the colors onto the ice. Don't pour too much at once, an eyedropper or even a spoon would be helpful. Also BE CAREFUL. Salt lowers the freezing point of ice, so the ice gets colder . If you have salt on your skin and then put ice on it, you can get a minor form of frostbite. So I would not recommend touching these ice cubes or the salt water colors with your bare hands. It is the salt lowering the melting point that makes this work (it is also what allows you to make your own ice cream). When you add salt the ice immediately around it starts to melt. The salt then slowly melts a tunnel through the ice. If you do this outside, not only will the warmth help melt the ice cubes faster, the light makes the ice cubes look really cool (no pun intended).

Learn more:
http://antoine.frostburg.edu/chem/senese/101/solutions/faq/why-salt-cools-icewater.shtml
http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch15/colligative.php
http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/meltpt.html#c1