How to make blobs in a bottle with a Lava Lamp effect

The World's Easiest Lava Lamp! This is an easy, fun science activity that is great for any age. In fact, our video crew ended up taking the extra bottles home to show their friends. It is also a great demonstration of liquid density, the release of gases in a chemical reaction, acids and bases, intermolecular polarity, and well, just plain science coolness.

YOU WILL NEED:
* A clean 1 liter clear soda bottle
* 3/4 cup of water
* Vegetable Oil
* Fizzing tablets (such as Alka Seltzer)
* Food coloring

WHAT TO DO:
1. Pour the water into the bottle.

2. Use a measuring cup or funnel to slowly pour the vegetable oil into the bottle until it's almost full. You may have to wait a few minutes for the oil and water separate.

3. Add 10 drops of food coloring to the bottle (we like red, but any color will look great.) The drops will pass through the oil and then mix with the water below.

4. Break a seltzer tablet in half and drop the half tablet into the bottle. Watch it sink to the bottom and let the blobby greatness begin!

5. To keep the effect going, just add another tablet piece. For a true lava lamp effect, shine a flashlight through the bottom of the bottle.

HOW DOES IT WORK?
To begin, the oil stays above the water because the oil is lighter than the water. The oil and water do not mix because of something called "intermolecular polarity." That term is fun to bring up in dinner conversation. When you added the tablet piece, it sank to the bottom and started dissolving and creating a gas. As the gas bubbles rose, they took some of the colored water with them. When the blob of water reached the top, the gas escaped and down went the water. Cool, huh? By the way, you can store your "Blobs In A Bottle" with the cap on, and then anytime you want to bring it back to life, just add another tablet piece.