We picked up a copy of Steve Spangler's Naked Eggs and Flying Potatoes for J recently. From what I've seen so far, I would highly recommend it if you're in the market for some fun science experiments. The book has a wide range of activities for various ages and skill levels. Some of them are much more in depth than others, but it looks like all of them are done with items you can find around the house, though you may have to hunt for some.
The first experiment we did was the Color Changing Milk, and I am hooked! This experiment was SO much fun. J and I both loved it. I also love that Spangler's book has simple explanations for how each experiment works. I didn't read word for word, but skimmed over it and explained it to J myself.
Basically you fill a dinner plate with milk and then add a couple of drops of food coloring as shown. Then you take a plain dry q-tip and hold it in the center of the plate for several seconds. If all goes well, nothing should happen :).
Then you dip a q-tip in liquid dish soap and once again hold it in the center of the plate. If all goes well this time, the colors should jump towards the edge of the plate and away from the q-tip.
Once we got things going we kept adding drops of food coloring and swirling.....
....and added and swirled....
...and added and swirled...
It was so fun to watch the colors mix and isn't it beautiful!?
Eventually things started getting a little muddy.
I'd tell you the science behind it but that wouldn't really be fair to Mr. Spangler, so I guess you'll just have to get your hands on a copy of his book and find out for yourself.
I would recommend this to any age, even if you have pre-k's that won't understand the science, I still think they would love watching the colors dance!