You will need access to water for this activity.

We suggest students work in pairs and two pairs of students share supplies at a group table. Homeschool students can work on their own.

Plan Your Time

You may want to divide this activity into two sessions.

• Part 1 (testing substances) takes 15 to 20 minutes.
• Part 2 (creating goo) takes another 15 minutes. Begins at Step 12.

To make the baking soda solution, use your 1-cup container to mix 1 cup water and 1 teaspoon baking soda.

To make the glue mixture, mix equal amounts of glue and water in a mixing bowl. This glue mixture will be enough for both parts of the activity.

To make the borax solution (for up to 32 students), in the other mixing bowl, mix 8 teaspoons borax powder with 4 cups warm water. It is okay if all of the borax powder doesn't dissolve. This borax mixture will be enough for both parts of the activity.

If you are splitting the lesson between two days, just keep the mixtures covered so they don’t dry out.

Prepare the Straws

Students use straws as pipettes for transferring liquid from a Dixie cup. Regular-length straws cause Dixie cups to tip over and spill. To prevent this from happening:

• cut each straw in half.
• lay the straws side by side with their ends squared up.
• eyeball ½ inch away from the cut edge and lay a ruler down at this point.
• draw a line across the straws using a permanent marker, as shown below.

Prepare the Testing Supply Cups for Part 1

• Count out 6 cups for each group of 4 students (or homeschool student).
• Use a permanent marker to mark cups for each group.
  • W for Water
  • S for Baking Soda solution
  • B for Borax solution
  • G for Glue/water mixture
  • V for Vinegar (If you use paper cups, be aware that vinegar will leak through some brands after an hour and a half. Plan accordingly.)
  • M for Milk
• Put 1 tablespoon of the corresponding supply in each cup.

Prepare the Mystery Goo Cups for Part 2

Using the remaining Dixie cups, you’ll prepare a cup of glue mixture and a cup of Borax solution for each student. * Add 2 Tbsp of glue/water mixture in half of the Dixie cups. * Add 1 Tbsp of borax solution in each to the other half of the cups.

Note that for homeschool students, you can always make a larger batch of goo as long as you mix the glue/water mixture with the borax solution in a 2:1 ratio.

Separate Supplies for Easy Distribution

In Part 1, your students will first practice using a straw to put water onto their testing mat. They’ll need the following supplies for this:

Then, students will combine and test different substances to see if they react. Students will share supplies with others at their table and will need the following:

In Part 2 of the activity, students will each create their own small bag of goo to take home with them. They will each need the following supplies:

You may want to set up supply stations for easier classroom distribution.

Borax, while safe when diluted, can be a mild skin irritant to some people, especially those with sensitive skin. If you are concerned, you may want to consider having your students wear gloves or use one of our Alternative Goo Recipes here .