The Science of Slime

Slime is such a fun toy! It’s ooey, gooey, and so squishy! While it may be a fun hobby for children and teens, slime can also be a great way to learn some science. The very existence of slime is based on chemistry!

A precursor to slime is oobleck. Some of you might remember reading about oobleck in Dr. Seuss’ Bartholomew and the Oobleck. You might have even recreated oobleck yourself using cornstarch, water, and food coloring. It sure is messy, but it’s fun to squish and squeeze!

Slime originated from Mattel Toy Company in 1976. It was primarily made of guar gum, a polysaccharide extracted from guar beans often used in food. The molecules from the guar gum are cross-linked with the added sodium borate, commonly known as borax. It came in a little trash can container in a variety of colors.

Perhaps a more familiar and recognizable slime is by Nickelodeon. Although it is a well-known children’s media company, it also has stocked stores with slimes created by them. Each year they also host the Kids’ Choice Awards, an event where kids can vote for their favorite celebrities, watch them perform, and see those celebrities get blasted with buckets of green slime.

After some close observation of how all the different types of slime flow and feel, one has to wonder if slime is a solid or a liquid. When squished and squeezed, slime feels kind of hard, but it can ooze through your fingers if you just hold it. This is particularly applicable to cornstarch and water oobleck. This is because oobleck and slime are non-Newtonian fluids. That means that their viscosity, or resistance to flow, changes under stress. The viscosity of oobleck and slime increase with applied stress.

This science experiment can be recreated at home using white glue, borax, and water. Single, unconnected molecules are called monomers. When identical monomers are chemically bonded into long chains of many molecules, polymers form. The polyvinyl alcohol molecules from the glue will cross link with the molecules from the borax solution. Polymers form from this reaction, causing slime to form.

Slime has been on the shelves of stores for decades under many different names, but they are all alike in that it’s all chemistry-based. Whether it’s silly putty, slime in a trash can, oobleck, or homemade slime, they are all formed from a chemical reaction, resulting in long chains of molecules. That’s what makes slime so satisfying to squish and squeeze. Who knew chemistry could be so fun?