A bowl of Insta-Worms™ is really just a great experience with polymers and cross-linking.
Earthworms are pretty much accepted by most people but, other worms? Not so much! However, you can create a bowl of worms that everyone will enjoy. Squirting Worm Goo into some Worm Activator instantly creates soft, shimmering, worm-like tubes. It’s a great way to combine polymers and cross-linking to create handfuls of science fun.
Insta-Worms™ is a trademark of Steve Spangler, Inc. All right reserved.
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- String Slime™ Goo
- String Slime™ Activator powder (or pickle juice)
- Large clear container
- Paper towels
- Adult supervision
Use the clear container to prepare some Worm Activator Solution. It’s best if it’s clear so you can see what’s going on inside the solution.
Pour 8 oz (240 mL) of warm water into the container. Add 1 teaspoon (or about 3 grams) of Worm Activator to the water and stir it. Make sure most of the Worm Activator is dissolved into the water completely before you move on to the next step.
Squeeze a steady stream of the Goo into the Activator and move your hand in a circular motion over the container as you’re squeezing. (Notice how the Worm Goo instantly turns into a long stringy worm?) It’s cool to watch but don’t let the top of the Goo bottle touch the Activator solution because you don’t want to contaminate it.
You know you want to touch it… so reach in and grab your Insta-Worm. Take it out of the solution and play with it– uh, that is, study it closely. The worm has elastic qualities like a rubber band. It can break if you tug it too hard, though.
You know what? Go ahead and break the worm.
What do you notice about the inside of the worm of both open ends? It’s still a gooey liquid inside!
Insta-Worm surgery is really simple. Just dip the broken ends of the pieces into the activator solution and it reseals. You’ve saved your worm and now you have two of them.
How Does It Work
The creative scientists at Steve Spangler Science coined the name, Worm Goo, but the real name of this liquid is sodium alginate. Sodium alginate is a long chain of repeating, identical molecules called a polymer. (Sodium alginate is a polysaccharide – or “many sugars” – taken from a seaweed.) Polymers are long molecules made from many (millions of) smaller molecules joined together. Polysaccharides, such as starch and alginate, are made by linking together bazillions of glucose (sugar) molecules.
Sodium alginate polymer chains (the Worm Goo) instantly change from a liquid to a linked solid the moment they touch the Worm Activator solution. Calcium ions in the Worm Activator solution link the long alginate chains together. Scientists call this “cross-linking.” This occurs because Ca++ ions replace Na+ ions and serve as the cross-linking agent between two alginate polymer chains. The resulting cross-linked polymer is insoluble in the calcium chloride solution of the Activator Solution and this results in the formation of a solid polymer strand. This reaction happens so fast that the Worm Goo in the middle of the tube remains liquid inside the cross-linked wall. See? Now you know!
Alginate is commonly used as a thickener for foods such as ice cream and fruit pies. Now that you know this chemistry secret, take a look at some food labels the next time you’re at the grocery store. Discover which foods contain sodium alginate. Your dentist uses alginate compounds in dental impression materials and it’s found in wound dressings in hospitals, too.
Take It Further
Ways to Experiment with Worm Goo
- Tiny Worms – Squirt a narrow stream of Worm Goo to make skinny worms. You’ll need to use (or make) a smaller nozzle.
- Worm Eggs – Drip single drops of Worm Goo into the Activator solution to make perfect “Worm Eggs.”
- Hard Worms – The longer the worms stay in the Activator solution, the firmer the texture of the worm will become. Knowing how they’re made, you can probably describe what has to chemically happen in order to make the interior of the worm harden.
- Color-Changing Worms – Add 10 drops of yellow food coloring to some Activator solution. When the blue Worm Goo touches the yellow Activator, the color of the worm changes to green! You’re mixing pigments.
- Wear-a-Worm – Turn your favorite worm into a necklace to totally gross out your friends!
- Dehydrated Worms – Allow a worm to sit out on a dinner plate undisturbed for several days. Notice how the worm shrinks as it dehydrates (loses water). Eventually, the worm will completely shrivel and become a long, thin, plastic thread. As you might have guessed, the water in the middle of the worm has evaporated leaving only a thin worm skeleton. Don’t worry – more worm medical miracles: fill the plate with water and watch the worm rehydrate over time!
- Intestines – Some people like to make really thick worms by squeezing a fat stream of Worm Goo into the Activator solution from a large nozzle opening. Notice how these worms are fragile because of their large, liquid center. Just wait… someone always says, “Hey, you made guts!”
Insta-Worms are great for learning about polymers and chemistry, but you must remember to be a safe scientist and follow the safety tips.
- This is not a toy. It is for demonstration purposes only.
- Always wear appropriate protective gear while conducting scientific activities.
- The chemicals in this activity are considered by the experts to be non-hazardous. Although Insta-Worms are considered to be safe to handle, squeeze, and experiment with or to mix with other household materials like those mentioned in these instructions, you should never put chemicals in or near your mouth, eyes, ears, or nose.
- Colored Insta-Worms can stain skin if handled for extended periods of time. The stain fades over time. Wash hands thoroughly with an oxygenated cleaner (such as OxiClean®) after handling for quick stain removal.
Dispose of the experiment materials properly. Worm Activator solution can be stored at room temperature in a closed container for future use. If you are disposing of it, pour it down the drain. When disposing of Insta-Worms and Eggs, throw them into a trash receptacle, not the garden.