Monday, November 15, 2010
You will need:
a plastic 2-liter bottle
Here's how to make your own lava "lamp":1. Fill any cup, like a large plastic party cup, with water.
2. Add food coloring of your choice until you have a nice, vibrant color.
3. Take a nice, clean 2-liter bottle. Fill it a little over halfway with vegetable or canola oil.
4. Add your cup of colored water to the oil.
5. Add more oil if necessary, to fill about to the top.
6. Put the cap on your 2-liter bottle. Gently tilt the bottle onto its side. What do the oil and water look like now? (We drew a picture in our workbook, for future reference.)
If you leave your lava lamp out for any length of time, you will notice that the oil and water molecules separate almost completely. Interestingly, the water is denser than the oil, so it will sink to the bottom; the oil will rest on top.
(Density is how much an object weighs compared to the space it takes up. So if you have the exact same amount of water and oil -- say, 2 liters of each -- the water will weigh more than the oil. It is denser.)