60 Second STEM: Density
Food coloring (optional)
(optional) Use the food coloring to dye the water and corn syrup your choice of different colors. This isn’t needed, but does make it easier to see what is happening.
Measure ½ cup of the oil and add it to the glass.
Measure ½ cup of the water and pour it into the glass. What do you notice happening?
Measure ½ cup of the corn syrup and pour it into the glass. Does the corn syrup remain in the top layer or does it sink?
Make it an experiment:
Ask a testable question about this demonstration and then explore it. For example, do these liquids always fall out into the same layers, or does temperature affect where each liquid rests?
With this investigation we are exploring density! Density is a measure of how much stuff an object has packed into it when compared to objects of the same size. Denser objects are more tightly packed and have more stuff in them than less dense objects. If you compare, for example, a baseball and styrofoam ball, they may both be the same size, but a baseball is much heavier--it is denser. These different densities can affect how these objects act in the world. If we were to throw both balls in a pool, the denser object (the baseball) would sink.
In our investigation we are comparing the same volume of three different liquids. If these liquids were identical, they would mix or stay in the order in which they were poured. The liquids have different densities which means, just like our balls, they act differently. Denser liquids, like the corn syrup in our example, will sink, and less dense liquids, like oil in our example, will float. Of course, if you added a liquid that was less dense than the oil, then the oil would also sink.
Click here to watch Hannah from Shoestring Science explain and complete this investigation