At-Home Science Experiment: Making Gak

Gak, also sometimes called Flubber, is a stretchy, rubbery ball of goo that is fun for kids to play with and to make as a learning activity, too!

How it works
By combining ingredients, you introduce two different substances – Elmer’s glue and borax – that bind together to form a polymer that happens to be particularly fun to play with.

What is a polymer?
Polymers are strings of molecules (for younger kids, explain that molecules are the building blocks that make all materials, like plastic, water, even our bodies!) attached to each other in long chains. Different polymers look, act and feel different. Some are hard and tough – like a table top – and some are gooey and rubbery, like the Gak you’re about to make!

Making Gak
NOTE: This activity requires supervision! Because Gak contains Borax, it cannot be eaten or placed on furniture. Food coloring, if used, may also stain clothes and carpet.

Follow this recipe from the A to Z Home’s Cool Homeschooling website, and make sure to take a look at their cute how-to vlog, too!

• 1. Mix thoroughly:

• 1 1/2 cups very warm water
• 2 cups Elmer’s glue
• Food coloring (optional, as could stain clothing and skin)

• 2. In a separate bowl, mix thoroughly:

• 1 1/3 cups very warm water
• 2 level teaspoons Borax

• 3. Mix the contents of the two bowls together kneading until it is fully combined. Discard any remaining liquid.

More Chemistry lessons for the kids
Illustrate the concept of a polymer by creating a chain out of loops of construction paper. What happens when you pull the paper chain end to end? (Answer: It stretches.) What happens if you try to pull the paper chain side-to-side? (Answer: It breaks.)

Polymers act the same way. Applying different forces to your Gak will make it stretch or break because of the polymer chains inside of the materials.