Idea from https://sciencebob.com/blobs-in-a-bottle-2/
Materials:
1. 1 500ml clear glass mineral bottle
2. 3/4 cup of water
3. 1 bottle cooking oil
4. Fizzing tablets such as Alka Seltzer (you can buy from a local pharmacy)
5. 8 drops of food coloring
6. 1 funnel (optional)
Directions from https://sciencebob.com/blobs-in-a-bottle-2/:
1. Pour some water into the bottle until it is roughly 20% full.
2. Slowly pour in the cooking oil into a bottle (using a funnel if you wish) until it is almost full.
3. You may have to wait a few minutes for the oil and water separate.
4. Add 8 drops of food coloring to the bottle.
5. You will notice that after a short while, the drops will pass through the oil and mix with the water below.
6. Drop in half a Alka Seltzer tablet and watch it fizzing up the bubble :-)
7. 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.
Additional Information:
The website explains it as follows:
"To begin, the oil stays above the water because the oil is lighter than the water or, more specifically, less dense than water. The oil and water do not mix because of something called “intermolecular polarity.” That term is fun to bring up in dinner conversation. Molecular polarity basically means that water molecules are attracted to other water molecules. They get along fine, and can loosely bond together (drops.) This is similar to magnets that are attracted to each other. Oil molecules are attracted to other oil molecules, they get along fine as well. But the structures of the two molecules do not allow them to bond together. Of course, there’s a lot more fancy scientific language to describe density and molecular polarity, but maybe now you’ll at least look at that vinaigrette salad dressing in a whole new way.
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."
To make further experiment, you can ask your child to try out:
Does the temperature of the water affect the reaction?
Does the size of the bottle affect how many blobs are produced?
Does the effect still work if the cap is put on the bottle?
Does the size of the tablet pieces affect the number of blobs created?
We tried this today, while Baby C was taking her nap. J was 7Y3M28D old. He enjoyed it very much :-)
References:
https://sciencebob.com/blobs-in-a-bottle-2/
1. Pour some water into the bottle until it is roughly 20% full.
4. Drop in half a Alka Seltzer tablet and watch it fizzing up the bubble :-)
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.
2. Slowly pour in the cooking oil into a bottle (using a funnel if you wish) until it is almost full (you may have to wait a few minutes for the oil and water separate.)
3. You may have to wait a few minutes for the oil and water separate.
4. Add 8 drops of food coloring to the bottle.
5. You will notice that after a short while, the drops will pass through the oil and mix with the water below.
6. Drop in half a Alka Seltzer tablet and watch it fizzing up the bubble :-)
6. 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. We haven't done so yet.
Updates: 17 July 2016
