 Welcome back to Kids Fun Science. My name is Ken. Today's experiment is cocoa powder that can't get wet in milk. So what you need for this experiment is milk. I'm using 1% and fat-free and some water, a toothpick, a glass, cocoa powder, and a spoon. So I'm going to do three different experiments and we're going to make prediction on each one. So the first experiment is with 1% milk. So as 1% milk will get wet in cocoa powder. So here we have, we have a spoon, we dip it in and we pull it out and it gets wet. But here's the fun experiment. When you pop it with a toothpick, it takes all the liquid off and it comes dry again. And you can do it over and over, which is pretty cool. So here it is again. And you just get faster, you pop it, the quicker it comes out. So I didn't hit it hard, hit it there, kind of went in. But when you do it again and you hit it really quick, it goes back to powder very quick, which is pretty cool. So the second experiment is with water. So will water get the cocoa powder wet? So here we go in the second experiment, make your prediction, put it in the water and pull out and it does not want to stay wet. It automatically is just going right back to the cocoa powder. So that was a fail. So the third experiment is with fat free milk. So will fat free milk get wet in the cocoa powder? Now it's got fat free. So we'll make your prediction and we'll put it in. And you see it's just like regular 1% milk. It does get wet and you do have to take the toothpick to make it dry. So the science behind this is oil and water don't mix. Oil repels water. Oil is hydrophobic. The fat molecules inside the cocoa powder are hydrophobic too. So they repel water. On the other hand, the starch molecules are hydrophilic. They love water. So milk is mostly water. So the same rules apply are true to milk. When you dunk the cocoa powder in the milk, the starch molecules quickly absorb the milk. At the same time, the fat molecules stop the milk from getting any further than the surface. This creates a shell on the milk around the outside of the cocoa powder. So when you poke it with the toothpick, it breaks the shell surface tension. The milk rolls off the cocoa powder and back into the cup. Science is pretty cool. If you enjoyed this video, please remember to like and subscribe. And thanks for watching.