Today's activity couldn't be easier or more fun. You've got the goods, right? The clear bottle, water, funnel, cooking oil, glycerin, and food coloring?
To make a Liquid Sandwich use the funnel to fill the bottle one third full with water. Drip 4 or 5 fat drops of food coloring directly into the water. Fill the bottle another third of the way with the glycerin and lastly with the cooking oil. That's it! What could be simpler?
Look at the way the liquids separate, will you? Like a liquid sandwich, wouldn't you say? The bottom layer is oh, so glycerin clear. The middle layer is oceanic blue topped of with sunny golden cooking oil. Kind of poetic, isn't it?
A word of warning, though. To keep these distinct layers separate you will need to handle your Liquid Sandwich with care. I wouldn't shake it up, if I were you. When it gets shaken the glycerin mixes with the water. The end result is something like the Ocean in the Bottle we made a few weeks ago. It's cool and still fun to play with, but the clear glycerin layer is gone...or is it?
Where does it go? Why does this mixing of liquid layers happen, you ask? What is your hypothesis? Something to do with the molecular structure of the liquids, I'll bet. You think?
You know, my Simple Saturday friend, this activity would make a dynamite project for your school Science Fair. Of course, you would have to do a wee bit of research to explain the scientific reasoning behind the liquid separation. Wouldn't it be fun to study the science behind an activity as fascinating as this one?
Isn't that what the scientific process is all about? To find out more about something that interests us? Don't we state our hypothesis, or our own reason why we think something is happening, and then set out to prove it?
Well, go for it, Einstein. Let me now what you find out!