Lava lamp

Homemade Lava lamp 

How to make lava lamp

1. Rinse out a large soda or water bottle. Any     tightly sealable container works, but you probably have an empty water bottle laying around somewhere. Try to find one that holds at least 16 ounces or 500 milliliter, so you can clearly see the display.                                                                        
#This method is safe for kids to follow on their  own, and much faster and easier than making a  permanent lava lamp. Young kids can ask an adult  to do the pouring for them.
                                                                                   2. Add oil, water, and food coloring to the bottle. Fill the bottle ¾ of the way full with vegetable oil, then top it off with water and about 10 drops of food coloring (or enough to make the solution appear fairly dark).

3.Add salt or an Alka-Seltzer tablet to the water. If using a salt shaker, sprinkle it in for about five seconds.[1] For a more exciting, fizzing lava lamp, instead take an Alka-Seltzer tablet, break it into a few pieces, and toss them all in.
Any other tablet labeled "effervescent" will work. These are often sold as Vitamin C tablets at drugstores.

4.Put the cap on and tip the bottle back and forth (optional). This will cause the tiny droplets of colored water moving around inside the oil to join together, making bigger lava-squirt blobs. That's what scientists call them, anyway.
                                                                              Add more salt or another effervescent tablet whenever the blobs start moving.                                                                                                              5.Place a strong flashlight or searchlight under the bottle. This will illuminate the bubbles for maximum effect. But don't leave your bottle on top of a heated surface! Plastic will melt and you'll get oil everywhere.

6.Understand what's happening. Oil and water never mix into one fluid, instead just breaking into the strange blobs you see slipping past each other. Adding the last ingredient really stirs things up. Here's why:

Salt sinks down to the bottom of the bottle, dragging a blob of oil with it. Once the salt breaks up and dissolves in the water, the oil floats up to the top again. 


The fizzy tablet reacts with the water to make tiny bubbles of carbon dioxide gas. These bubbles attach themselves to the blobs of colored water and float up to the surface. When the bubbles pop, the colored blobs sink back to the bottom of the bottle.[3]