MOBILE, Ala. (WKRG) – Science Corner with Meteorologist Caroline Carithers showing you how to make your own lava lamp (and why it works)!
Needed Supplies: Water, oil, food coloring, Alka-Seltzer tablets, clear mason jar
Steps (check out the video for a visual!):
- Fill jar 3/4 full with oil (vegetable oil is best, but olive oil works)
- Add about 2 inches of water
- Add several drops of food coloring
- Add crushed Alka-Seltzer tablets one piece at a time
- Watch your lava lamp come to life!
Explanation: Why don’t oil and water mix? Very simply, it all comes down to the fact that water molecules (what makes up water) are polar (has 2 poles – one positive and one negative at each end, like a magnet!) and oil is not. It is like trying to stick a magnet to something not magnetic; it does not mix!
Why does water sink to the bottom of the jar with oil floating on top? The answer is water is more dense (more mass per volume – very simply – more compact molecules) than oil so it sinks! For example, a styrofoam cup is less dense than a ceramic cup, so the styrofoam cups floats while the ceramic cup sinks. Same goes for wood and a rock. Wood is less dense than a rock, so the wood floats and the rock sinks!
Food coloring is water-based so it sinks as well! The Alka-Seltzer tablets create a chemical reaction that allow the bubbles to rise, pop and sink!
Check out the video to see the experiment start to finish!
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