Lava lamps are really fun and inexpensive to make at home. They bring a great deal of enthusiasm to a science lesson. When you make a homemade lava lamp the first thing to observe before you drop the alka seltzer tablet in the bottle is the separation of oil and water. You can see that oil is lighter or less dense than water. When you drop the alka seltzer tablet into your bottle the tablet begins to release gas bubbles. These gas bubbles force some of the water molecules through the oil. When they reach the top the gas is released and the water sinks again to the bottom.
I really like to use the Voss water bottles. They look so cool! It makes your lava lamp look like the real thing. As an added bonus the labels easily peel off. A quick squirt of goo be gone removes all the sticky residue and you are in business. A little tip, encourage the kids not to shake their lava lamps before putting in the alka seltzer it dampens the affect.
