July 24, 2012

Make a Lava Lamp




Lava lamps are awesome and so fun to watch! 
Here’s how to make a homemade version of a dazzling lava lamp:

Get a clear jar (glass or plastic). It has to be a container with a secure lid. A 64-oz soda bottle will do.

Rinse the container thoroughly with clean water to ensure that all contaminants and impurities are removed.

Now, fill ¾ of the container with vegetable oil. Add water to fill up the remaining space inside the container. Put a few drops of food coloring (your preferred color) until you see that the water solution appears fairly dark. The oil layer will remain separated from the colored water layer.

If you want, put some glitter dust to add some sparkle to your lava lamp. Add a pinch or two of table salt. Do you see the bubbles? Now, shine a flashlight behind your lava lamp and see how it glows!

You can place your lava lamp on your bedside table. Tap it now and then, and watch the strange liquid shapes form and move inside the bottle.

Here’s the science behind this amazing homemade lava lamp: oil is less dense (lighter) than water, so it rises to the top of the container. Table salt, on the other hand, is denser (heavier) than water, so it sinks. But then oil also gets attached to the salt crystals while the salt crystals sink. Salt dissolves in water, and the attached oil blobs do not mix with water. Thus, when the salt crystals dissolve, the oil blobs rush upwards to the top and you see the bubbles.


For more easy and fun science facts, projects, and activities like these that are perfect for your grade-schooler, be sure to check out “The Amazing Science Discovery Series”. 


5 comments:

  1. Wow! This is so cool!

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  2. Never in a million years would I have thought this could be made at home. So, so cool!

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  3. Thanks, I tried this today and I think my problem was that I used more water than oil.
    Would that have made a difference? I just thought that the "blob" would be smaller, but...
    The oil and water didn't mix, but there was no that much action in the bottle. Do you think it needs majority oil? Thanks so much!

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  4. Glad you liked the activity! The picture is a public-domain image from Wikipedia; it's a commercially made lava lamp so the separation is so much more pronounced. For the homemade lava lamp, the secret is in the salt; the more salt, then the more bubbles. But eventually the bubbling stops once all the salt crystals have dissolved. To sustain it, add salt once again.

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  5. OH! Thanks so much. That was obviously my mistake. Thanks for the advice that will help me to keep it going too!

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