Using Observations to Explain Common Phenomena

Lab #1 What Difference Does Milk Fat Make? Materials aluminum pie pan wooden splint toothpick liquid dish detergent whole milk food coloring (4 different colors) I gathered the materials and then poured whole milk into a shallow aluminum pan. The milk came to a depth of about 1 cm. I then added a few drops of water-soluble food colorings in the outer edge of the pan. The drops of different colors were placed at these hour positions on a clock: 3, 6, 9. And 12 (Bodine, 2014).

Next, I dipped a toothpick into detergent and just touched the surface of the milk right in the center of the container, but I held the toothpick still in that place for a while. Soon, the food coloring on the surface of whole milk seemed to sort of dance and move around (Bodine, 2014). The fat globules in the whole milk holds tight to the dish soap, forming a sort of bond that pushes away the food coloring and the water in the milk as the bonds form (Bodine, 2014).

Just to test the theory about the fat and dish soap bonding, I tried different types of milk. With 2% milk, there was some activity of the dish soap, and with 1%, there was even less. Skim milk did not produce the effect at all. I also tried soy milk and almond milk, but no effect was seen. When I tried half-and-half, the activity of the dish soap and the fast globules was exaggerated beyond what I saw with whole milk.

The hypothesis of this experiment is that the nature of dish soap causes it to bond with fat (or grease, as the dish soap advertisements claim). A dish soap that functions as promised in the ads should produce a lot of activity with the fat globules, which is nicely revealed by the food coloring in the watery portion of the milk (Helmenstine, 2015). Lab #2 Measuring the Metric Way Estimate each of the following dimensions in meters, decimeters, centimeters, or millimeters.

Then get a measuring device (like a yard stick that also has metric units or a tape measure that has metric units) and determine how close your estimate comes to.