Slime Time

Age

Elementary School, Middle School, High School

Format

Hands-on

Materials

   Water
   Borax (sodium tetraborate)- available in the laundry section of most grocery stores
   Elmer’s glue (not the washable kind)- also available at any general store
   Popsicle sticks or spoons
   Large mixing bowl
   Ziploc bags
   Paper towels 

Safety Precautions

Science Theatre demonstrators must keep the safety of themselves and their audience in mind at all times. All Science Theatre demonstrators must have read through the Safety Training page. The ST Safety Box with first aid kit, fire extinguisher, etc. should always be available to demonstrators. Always wear safety gloves, glasses, and a labcoat if handling chemicals; always perform potentially dangerous demonstrations at a safe distance from the audience; and always keep a very close eye on any volunteers you call from the audience. Creates a non-toxic slime, but eating it is not recommended.

Borax (Sodium Tetraborate) MSDS

Preparation

Create a super saturated solution of water and borax.

Demonstration

Add Elmer’s glue to the solution (2 tablespoons, but measuring not necessary) Stir rapidly with Popsicle stick. Check the slime, if it is very sticky keep stirring it in the borax solution, if it is no longer sticky proceed to step 5. The slime should feel very runny and be difficult to hold in your hands. Scoop out the slime and knead between hands. The longer you knead the more putty like the slime will become. Store slime in a plastic bag, if it starts to dry out add more water.

What to Say

Have the kids add the glue and stir the glue into the borax solution. Explain that this is to change the glue into slime by causing it to form long molecular chains. The slime will feel very wet and gooey at first; this is a result of too much borax. Have the kids knead the slime, they usually enjoy getting their hands all slimy. The kneading will cause excess borax to evaporate or be absorbed leaving a Silly Putty-like substance behind.

Why It Is

Mixing glue with water creates a polymer (polyvinyl acetate); the borax links the polymer chains together.

Real Life Examples

Polymers are used all the time around the household. Plastic, nylon, and clothing all contain polymers. For example, fishing line or any plastic object is made of polymers. Gak (if anybody remembers that from when it was cool…) is a very similar polymer (polyvinyl alcohol) to what this experiment creates.