Today at the GSC we are making our own lava! Well, sort of… this lava won’t burn or harm, but it sure looks cool!!
* A clear drinking glass
* 1/4 cup vegetable oil
* 1 teaspoon salt
* Food coloring (optional)
- Fill your glass about ¾ full of tap water, and add your food coloring.
- Slowly pour ¼ cup of vegetable oil into your glass. You should notice that the oil floats on top of the water.
- Now for the cool part: Sprinkle salt on top of the vegetable oil. You should see the oil start to move up and down in the glass!
What did I just watch?
Oil is less dense than water, therefore, it floats on top of water. Since salt is heavier than oil and water, it sinks down to the bottom of the cup. Some oil sticks to the salt as the salt sinks. But, as the salt dissolves in the water, the oil makes its way back to the surface!
As always, it is important to note that an experiment uses a variable (something that changes) to answer a question. To turn this demonstration into an experiment, you have to change something! Check out these questions to get you started:
- Do different types of food oil respond differently to salt being added?
- Does the size of the glass effect the outcome?
- Does the amount of oil change the bubbling effect?
- Does the type of salt change how the oil sticks to it?
Give it a try and let us know how your experiment turned out on our Facebook, Instagram, or Twitter pages using the hashtag #gscscience!