It's been nearly a year since we've made an oil, and water "lava lamp", and last time we use Alka Seltzers to keep our bubbles moving.
This time, we started with six glass jars, filled 3/4 full of water.
Then, we added food coloring to make our rainbow (just two drops in each jar)...
...topped the jars off with 1/3 cup of cooking oil each...
...and dumped in some table salt.
Just as Family Fun promised, the salt weighted the oil down, causing it to sink under the water, then as the salt dissolved, the oil "bubbles" were released, and rose to the top.
It wasn't quite as much fun as the Alka Seltzer version, but it was interesting to see the oil straining against the salt, as it dissolved, trying to rise to the top.
And, we noticed the colored salt water against the layer of oil, had a neat, ocean like effect.
So, of course, we had to make an "ocean bottle", again with oil, water, food coloring, and salt...
...but also with toy sharks...
...and a Lego "scuba" diver.
After oohing, and aahing over the larger "lava lamp", the little ones, who only vaguely remember our previous oil and water experiments, took it to swoosh waves back and forth...
...discovering in the process:
- no matter how much you shake the bottle, the oil and water will not mix,
- oil always rises to the top of the water,
- the food coloring will only dissolve in the water, and not the oil,
- our toy sharks do not float,
- our Lego man floats in water, but not in oil.
All in all, it was a very interesting, and satisfying experiment. Oh, and the children want you to know, that no shark, or Lego toys were harmed in the process.
Don't forget to check out this week's Science Sunday link-up, over at Adventures of Mommydom, for more science themed fun.
It's great to be a homeschooler.