Science Spotlight

Diffusion

Background Knowledge

Did you know that science is happening all around you, even when you are cooking? Have you ever wondered how pasta noodles go from hard and crunchy to soft and ready to eat? You might think that the noodles are absorbing the water, and you’re right! This is a cool science phenomenon — Diffusion! 

Diffusion is an important process happening everywhere: in the cells of our bodies, roots of plants, and even in your dinner prep. So what is diffusion? Molecules, the small particles that make up everything in our world, like to be spread out evenly. Diffusion is the process where molecules move from high concentration, where there are a lot of them, to low concentration, where there are fewer. In the example of our noodles, the uncooked noodles have a low concentration of water molecules. When cooking, the water will diffuse into the noodles, making them softer.Once the noodles are cooked, the molecules will be spread out evenly. If you don’t want to cook up any spaghetti right at this moment, try this easy science experiment instead.

Materials: You will need two glasses of water, one hot and one cold, and food coloring (one color works, but two is more fun).

Directions: Take the food coloring and place a few drops into each glass of water. What do you notice?

How it works: The temperature of a substance is related to how fast the molecules are moving. Therefore, in the hot water the molecules were moving faster than they were in the cold water. This causes the dye in the hot water to diffuse, or move throughout the water, more quickly!

Want more? Research It! Diffusion happens in things as small as a single cell. Do some research and find out how!