I mentioned in my 'Cloud in a jar' post, how I'd recently made a list of exciting experiments to do, that required few items. After our successful 'cloud in a jar' we tried our very own lava lamp!
This is such a simple experiment, I can imagine we have many lava lamps to come....so it's not quite a lamp but more like lava in a glass.
What you'll need
- Glass, we used a drinking glass (clear glass)
- Salt (approx 1tsp)
- Vegetable oil (to fill 1/4 of the glass)
- water (to fill approx 3/4 glass)
- Food dye (any colour - we used red)
What to do
Add 3/4 water to the glass, and add 4/5 drops of food dye (not too much as don't want a deep colour). Add the vegetable oil, which you will notice will float to the top (oil and water don't mix). Once all the oil as settled at the top, add about a teaspoon of salt.
You'll notice some of the oil clumping with the salt and sinking to the bottom of the glass. This oil will then rise back up, creating your Laval lamp!
What's happening?
As we know, oil and water do not mix. Depending how much your child knows, this can be discussed in greater detail, bring in densities and ask about other liquids that do or do not mix. What does it mean to have different densities?..and so on.
When you add the salt (the salt sinks as it has a higher density than water), some of the oil is, literally, dragged down with the salt. As the salt dissolves, the oil is 'released' and bubbles back to the top.
This can be done without food dye, but it looks much prettier with added colour!
Try it out and let us know how it went!
Comments
Post a Comment