Groovy Lava Lamp

Here's another fun experiment that we tried this week. It uses oil and water like the polar bear experiment, but this time Oliver and Buttercup were able to really see how oil and water do not mix.

You'll need:
an empty 2 liter plastic bottle, rinsed, with the cap
a large bottle of vegetable oil
water
liquid food coloring
a plastic cup
a funnel

First, fill a plastic cup with water, then add the food coloring of your choice (both of my little scientists prefer blue) and stir it up.


Pour the oil into the empty bottle until it's half full.


Then add the colored water to the bottle.


You'll see some pretty cool results immediately after adding the water.


Screw the lid on tight, then turn the bottle on its side and swish the contents around a little bit.


Even after a little jiggling, you'll see that the colored water molecules are still not mixing with the oil:


Then -- the kids' favorite part! -- shake the bottle as hard as you can to see if you can get the oil and water to mix!



Immediately after, it does look like the oil and water mixed together.


But 30 minutes later, it's easy to see that the oil and water are separating again:


And 10 hours later, they are almost completely separated. This is because oil is not as dense (heavy) as water, so the water sinks and the oil floats.