If you find yourself scratching your head with the latest slime obsession, keep in mind that making slime is actually science! Slime is chemistry! Polymers and Non-newtonian fluids can be a little confusing for young kids, but our short lesson in the science of slime is a perfect way to introduce the science behind the slime to your kids. We LOVE homemade slime!
START WITH THE BEST SLIME RECIPES
First off, have you ever made a really good homemade slime with your kids? If you haven’t (or even if you have), make sure to check out our collection of the BEST HOMEMADE SLIME RECIPES. We actually have 5 basic slime recipes which are the foundation for all our slime variations.
Making slime has proven to be extremely fascinating for kids and adults of all ages, but you might not be familiar with the basic slime science. This is great to share with kids who love slime because it’s an awesome learning opportunity already built into an incredibly fun hands-on activity.
THE SCIENCE BEHIND SLIME
Slime science starts with the best slime ingredients including the right kind of glue and the right slime activators. You can see all our recommended slime making supplies here. The best glue is a PVA (polyvinyl- acetate) washable school glue.
You have several slime activators to choose from (all in the boron family). These include saline solution, liquid starch, and borax powder, and all contain similar chemicals for making a slime substance. Cross linking is what happens when the glue and activator are combined!
WHAT IS SLIME?
Slime involves chemistry! Chemistry is all about states of matter including liquids, solids, and gases. It is all about the way different materials are put together, and how they are made up of atoms and molecules. Additionally, chemistry is how these materials act under different conditions.
Slime is a non-Newtonian fluid. A non-Newtonian fluid is neither a liquid or a solid. It can be picked up like a solid, but it also will ooze like a liquid. Slime does not have its own shape. You will notice your slime change it’s shape to fill whatever container it’s placed in. However, it can also be bounced like a ball because of it’s elasticity.
Pull the slime slowly and it flows more freely. If you pull it quickly, the slime will break off more easily because you are breaking apart the chemical bonds.
WHAT MAKES SLIME STRETCHY?
Slime is all about polymers! A polymer is made up of very large chains of molecules. The glue used in slime is made up of long chains of polyvinyl acetate molecules (that’s why we recommend PVA glue). These chains slide past one another fairly easily which keeps the glue flowing.
Chemical bonds are formed when you mix the PVA glue and slime activator together. Slime activators (borax, saline solution, or liquid starch) change the position of the molecules in the glue in a process called cross linking! A chemical reaction occurs between the glue and the borate ions, and slime is the new substance formed.
Instead of flowing freely as before, the molecules in the slime have become tangled and create what is slime. Think wet, freshly cooked spaghetti versus leftover cooked spaghetti! Cross linking changes the viscosity or flow of the new substance.
SLIME SCIENCE PROJECTS
You can experiment with the viscosity or thickness of slime using our basic slime recipes. Can you change the viscosity of slime with the amount of slime activator you use? We show you how to set up your own slime science experiments in the link below.
BORAX FREE SLIME
Concerned that borax is not good for you? We have a number of taste safe borax free slime recipes for you to try. Find out what fun substitutes for borax you can make slime with! Please note, that a borax free slime will not have the same texture or stretch as a traditional slime.
Feel like you are juggling between helping a few students and groups that finish at different times?
Want to know what to say when children ask those difficult to explain WHY questions?
24 pages of AWESOME slime science activities, resources, and printable worksheets for you!!
When it comes to doing science every week, your class will cheer!