Homemade Lava Lamp
Lava lamps are cool things to stare at for hours! In this simple science experiment, you’ll learn how to make a similar type of display (without the lights), and the science behind it.
Materials:
- Empty (wide mouth) glass bottle
- Water
- Oil
- Food coloring
- Alka-Seltzer tablets
- Glitter
Procedure:
- Fill a glass bottle halfway with water.
- Pour an equal amount of oil in. Make sure to leave some space near the top.
- Drop some food coloring into the bottle and watch it slide through the oil until it hits the water and then mix together.
- Add some glitter to the liquids.
- Place a light behind the glass bottle to enhance the magic.
- Drop the Alka-Seltzer tablet into the bottle and enjoy your lava lamp!
Explanation:
A lava lamp works because it has two liquids that don’t mix together. An actual (store-bought) lava lamp uses water and wax. The lamp heats up the wax until it melts and becomes slightly less dense than the water, making it float. Once it cools down, the wax becomes denser and then sinks. The process repeats…for your visually entertainment.
This homemade version also relies on two liquids that do not mix well: oil and water. The water has a greater density than the oil and, therefore, sinks. Density is a property of matter that shows how much stuff is contained within a space. Metal has a lot of density… it’s really heavy for its size!
When the tablet bubbles in the water, it makes the water less dense, in a sense, making it float up to the top of the oil. When it gets there, the air escapes and the water, denser again, sinks to the bottom.
Experiment further:
Good scientists think of questions they can ask and ways to change a system. Can you? How about if you change the size of the container? Or the size of the tablet? Maybe the number of tablets? What if you put in more oil than water? Ask any question you want and then test it out!
Steve Davala is a middle school science teacher who likes to write. He has two kids and subjects them to such science activities as guinea pigs. Follow him on Twitter or http://stevedavala.blogspot.com.
