by Ms. Robinson's Grade 2 Class
Question
When adding a drop of detergent to a plate of milk with food coloring, what kind of milk produces the best swirling of color: 1%, 2%, or whole milk? What happens to plain water?
Hypothesis
Based on our research we think that homogenized milk will create the most explosive swirl in this experiment.
Research
In class, we talked about how milk contains fat and proteins. When you add soap to milk, the molecules of fat move around in many directions as the soap molecules attach to the fat molecules, creating currents for the color to start to swirl in. We also talked about surface tension. Milk contains water which has surface tension. Soap breaks the surface tension of the water which also allows the colors to move around.