SLIME! Kids love the ooey, gooey, sticky, squishy, mess and moms dislike it for all the same reasons. I’m here to help you start to like slime. Especially when you see your child’s face light up with excitement and joy while making and playing with this slime.
Slime is the perfect science experiment for Halloween. Depending on the colors and add-ins used, it can be creepy, spooky, sparkly, glow-in-the-dark, shiny…you can match it to any Halloween costume or party theme.
My kids love slime, but we’ve never made it ourselves at home before. Since it’s our first dabble into slime making, I’m keeping this recipe classic and simple. I am using as few ingredients as possible, and we’re using ingredients you most likely already have at home.
Let’s talk about the science of slime
Slime is a non-Newtonian fluid, similar to Oobleck, which we learned about last month. This means that it changes viscosity, and flows more freely like a liquid when you let it fall from your fingers, but it can form a tight ball when compressed between your fingers and the palm of your hand.
Slime is made up of a PVA (polyvinyl-acetate) glue and activators. PVA glue is simply your everyday Elmer’s washable school glue. There are several borate ion activators you can choose from: Borax powder* (sodium tetraborate), contact lens or saline solution (contains both sodium borate and boric acid), liquid starch (contains sodium borate), or eye drops (contain boric acid).
The slime is stretchy due to cross-linking polymers. PVA glue contains polymers, which are long chains of molecules. When you add the activator (containing a borate ions), new chemical bonds are formed. It changes the position of the polymers, creating cross-linking which acts as a net to trap the liquid and keep the slime feeling wet, but remains a stretchy due to the long polymers chains.
- Helpful and informative slime resource: The Science Behind Slime by Little Bins for Little Hands.
*There is some controversy on the internet about the use of Borax or any of the borate ion containing activators. I have read both sides (read a case against Borax here and a case for Borax here), and I personally feel that borate ion activators are safe under supervised use for my children.
My slime recipe does not use Borax. It does, however, use saline solution which contains borate ions (the same active ingredient as Borax). If you don’t want to use borate ions, Little Bins for Little Hands’ website has many borate ion-free slime recipes here.
Easy Halloween Slime
This slime is easy and fun to make and play with. It’s great for kids age 2+, with adult help and supervision. You can make this as crazy and creepy or as simple as you choose!
Safety:
Always supervise your children while working with and mixing chemicals. This is NOT a taste safe experiment, so be sure to remind your children that the slime should never go into their mouth.
I recommend protecting your table or work surface while making and playing with the slime, and wear clothes that are ok to get stained. Slime will stick to fabrics and carpets and is extremely difficult to remove, hence why many parents don’t like slime. But with close supervision and proper instruction and preparation you don’t have to be scared!
As discussed in the science of slime section above, this experiment contains contact lens or saline solution, which contain borate ions. While our experiment does NOT contain Borax, the active ingredient – borate ions are also in Borax.
Prolonged exposure to Borax reportedly caused chemical burns on a few children who were making lots of slime. This is extremely rare, and preventable by following directions closely (which will call for dilution of the Borax), and wearing gloves, especially if you or your child have sensitive skin.
Materials Needed:
- Medium bowl
- 5 fl oz bottle of washable school glue (glow in the dark, glitter, color changing, etc…)
- 1/2 Cup water
- 1/2 Tbsp baking soda
- 1 Tbsp contact lens or saline solution (we used saline solution because it’s much less expensive than contact solution, but if you already have contact lens solution at home it will work fine)
- Spoon for stirring
- Optional – Halloween Add-ins (food coloring, google eyes, spiders, glitter, etc…)
Procedure:
- Pour the entire bottle of glue and the 1/2 cup water into a large bowl and mix well with your spoon
2. Optional – If you’re using any add-ins (such as color, glitter, spiders, etc…), stir them in now!
3. Add 1/2 Tbsp baking soda and mix well with your spoon
4. Add 1 Tbsp contact lens solution and stir with your spoon until it becomes harder to mix and slime begins to form
5. Take slime out of the bowl and knead with your hands
6. If it’s too sticky, add 1/4 Tbsp of contact solution and keep kneading. Add 1/4 Tbsp contact solution as needed until you get your desired consistency.
7. Play with your slime! Here are a few suggestions for more STEAM learning while you play:
7A. Pull on the slime slowly, does it stretch? Now pull on it quickly, did it break into two pieces?
7B. Let the slime ooze between your fingers
7C. Can you roll the slime into a ball?
7D. Can you roll the slime along the table to form a long snake?
7E. What else can your kids do with their slime? Here are a few of our favorites:
8. Store the slime in an airtight container or bag to play with over and over again
9. When the kids are tired of playing with the slime, drop it in a heap on wax paper to dry for a week. Don’t touch it while drying and it should form a cool shape to make slime art that your child will proudly display on their dresser. 😉
My kids haven’t gotten bored with their slime yet, so I don’t have pictures of this, but let me know if you try it!
What Happened:
You made an amazing and fun non-Newtonian fluid! It’s fluid but acts differently depending on the forces exerted upon it.
The polymers in the slime have covalent bonds between the molecules but hydrogen bonds between the molecules. The hydrogen bonds break more easily. Which is why when you pull on the slime it will stretch, but when you quickly pull on the slime it will tear apart.
Slime making is so simple, no wonder it has become such a big craze! It is quick and easy to whip up a new batch whenever you want, and it stores well to play with over and over again. Once you are done with your slime, you can let it dry out to make slime art!
There are so many ways to make slime that I think we will continue to try out more slime recipes and post them here as we find some that we like.
Do you like making slime at home? What is your favorite slime recipe?
