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Alginate Worm Kit

SKU #CK-600
Availability: In Stock
Make colorful, worm-like gels by combining two solutions.


Make colorful, worm-like gels by combining two solutions; sodium alginate (from seaweed) and the salt, calcium chloride. The calcium ions from the salt loosely bind the polymer alginate chains into a gel. With the addition of Red Cabbage Extract, students can watch the color-changing gel as it forms. The kit includes instructions, one liter of sodium alginate solution, calcium chloride salt, cups, forks, droppers, and a plastic tub. Enough for five stations.

Choking Hazard


Lesson Ideas

Download the pdf of this lesson!

Sodium alginate, also called algin, comes from a special large brown algae seaweed or kelp found in the Pacific Ocean. It has a very interesting property of forming gels in the presence of calcium ions. Now you can make some terrific, colorific wormy gel things by connecting, or bonding, alginate with calcium ions.

Recommended for ages 5 and up with adult supervision.

This Kit Contains: 1 liter 0.8 % sodium alginate solution with red cabbage extract, 25 grams calcium chloride, 5 cups, 5 forks, 5 droppers, small scoop, plastic tub and these instruction sheets.
You will need: water, paper towels, and various acids and bases such as lemon juice, baking soda, vinegar, clear ammonia cleaning solution, detergent containing sodium carbonate.

This is a safe and non-toxic chemical experiment kit when used as directed. However, anything can be dangerous when used in the wrong way. Always use any chemical, including household chemicals, with care. Do not drink or taste the chemicals in this kit. Keep the chemicals away from infants and young children. Always ask permission to use any household materials. Use safety glasses for Experiment 3. If any chemical gets on the skin or in the eyes or mouth, the best first aid is to wash with lots of water. Read the directions carefully. Never experiment with something you know nothing about. Experiment with small amounts of materials. It will be less dangerous and easier to control than large amounts; and you will conserve your resources. Keep the caps on the bottles when not in use. Calcium chloride is deliquescent. That means it will absorb moisture from the air. Discard the gels in the trash; do not put the gels down the sink. Wash with water, any cups, droppers, forks and the plastic container that you used in your experiments. Wash your hands and put away your materials when finished.

Experiment 1 Wormy Things
For our Alginate Worm Connections, we will use two solutions: Algy and Calcium. Chemists call a mixture of something dissolved in something else a solution. A solution also means an answer to a problem. In chemistry, you may be able to find a solution with the solution. Words can be confusing, so it is a good idea to use a dictionary.

Algy is our short name for sodium alginate. It is already mixed and is ready to use.

You will need to make a Calcium Solution. Take every thing out of the large plastic 'shoe-box' container that this kit came in. Put 2 cups of water in it. Add one capful of calcium chloride to the water, and swirl the box back and forth gently. The white pellets of calcium chloride will begin to disappear. They dissolve in the water.

Now we are ready for Algy to meet Calcium. Take the bottle of Algy and pop up the flip-top lid and squeeze one drop of Algy into the Calcium Solution. Look where the drop lands and see how it begins to react. Now add a squirt of Algy and see what happens. Take the fork and try to pull up the 'wormy thing'. It should be like jelly. You may be able to pull up a long string of jelly. Place it on the paper towel. Scientists call substances like this gels. They are safe to touch, but remember: Do not eat any of these experiments.

Add another squirt of Algy to the Calcium Solution. This time leave the worm in longer. Watch carefully. Can you see any changes? The outer edge of the 'worm' will begin to turn blue. It is reacting with something. More about this later.

How did it happen? When Algy meets Calcium, Calcium grabs and holds two Algy. And this is a new substance. A substance is a kind of matter that has definite chemical composition. We can call the wormy things 'Calgy'. Chemists call them Calcium Alginate. 'Calgy' is different than Algy and does not stay in the solution. It is not soluble in water and does not dissolve. Algy is made of long molecules called polymers and that is a key in forming the worms.

Experiment 2 Color Changing Algy
You will need lemon juice for this experiment.

First we will practice using the dropper. The dropper is also called a pipet, which comes from a French word meaning 'little pipe'. Pour some water into a cup. Then put the dropper tip in the water and squeeze slightly. Notice that air bubbles come out. Keep the dropper in the water and release the bulb. Look at the water move up the dropper. Squeezing the air out creates a vacuum, or empty space. Releasing the bulb allows the liquid to move into the empty space and fills the dropper. Hold the pipet over the cup and practice squeezing out one drop at a time.

Empty the cup and squirt about 1 teaspoon of the Algy Solution into it. The exact amount is not important. Then add a few drops of lemon juice to it. What happens? The Algy Solution will turn pink or light red.

Algy is a purple color because we put an amazing pigment, or colored material, in it - red cabbage juice. Red cabbage can actually change colors in the presence of different acids and bases. Lemon juice is a weak acid and acids will turn red cabbage juice red.

Look at the pH chart to the right. pH is a measure of acidity. What is the pH of Algy with lemon juice in it? What is the pH of the original Algy? Save the red Algy for Experiment 3.

Experiment 3 Worms of Different Colors
You will need different acid and bases such as lemon juice, vinegar, baking soda, clear ammonia cleaning solution and detergent containing sodium carbonate for this experiment. Caution: Do not use ammonia with young children.

Take 4 more cups and put about 1 teaspoon of Algy in each. In cup 2 add a few drops of vinegar, in cup 3 a little baking soda and in cup 4 add a little ammonia cleaner. What happens to each?

Cup 1 will be our control, and we can compare it to the others. A control allows the experimenter, that's you, to observe, or see, how changing one thing affects the experiment. This is very important so we can know what changed what. Scientists use controls to help them see how something causes something else to change. A variable is the something that can cause the change. In our experiment, the acids and bases are the variables. How will acids and bases change the wormy things? What is the pH of each solution?

If necessary, make more of the calcium chloride solution (1 capful in 2 cups of water) in the large container, as you did in Experiment 1.

When you are ready to make worms of different colors, use the droppers to squirt the different Algy mixtures into the Calcium Solution. You could also pour the Algy in. What happens?

What do you think is the best color or best pH to make 'Calgy'?

Chemists know that chemical reactions are often affected by the pH or acidity of the solution. Do you think pH makes any difference in forming the calcium alginate gel?

Experiment 4 Jelly Worm Eggs
We will make Calgy, or the calcium alginate gel, in a different way in this experiment and get a little surprise. Put a small squirt of Algy in a clean cup. Then use the small scoop and add 1 pellet of calcium chloride to the Algy. Watch it react or change. Pull it up with a fork. It will look like a jelly egg.

This time calcium chloride is dissolving in the sodium alginate solution. And as it dissolves, the calcium begin to react with the alginate. The 'skin' on the Jelly Worm Eggs is thick because there is lots of calcium nearby to react with alginate. Calcium is more 'concentrated' in this experiment than in the other experiments.

Chemistry of Algy Chemistry is the science what things are made of and how they change or react. We could see the 'Algy' change when it met Calcium in the solution. We could also see the color change. These are chemical changes or chemical reactions.

This is a model or symbol of 'Algy':

The actual molecule of Algy, or sodium algina

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5 reviews
Alginate Pearls and Worms
Review star icon Review star icon Review star icon Review star icon Review star icon Apr 15, 2019
Before I go any further, one person noted that the alginate solution degrades over time, which it does. However, we found that if one keeps the solution refrigerated when not in use, it will last for months, even years. Making alginate pearls and worms is not only great fun, but also can be used to explore concepts of polymers, cross-linking, solubility, natural materials, and uses in cooking, medicine, and possibly other areas we have not yet explored. The entire process of setting up, making the pearls and worms, and cleanup is quick and easy to do. We use small plastic food storage tubs to mix the calcium chloride into the water. The sodium alginate solution is poured into small plastic cups with disposable pipets in each cup. The plastic tubs and cups are reusable so with simple rinsing and hanging up to dry, they can be stored and ready for use next time. At outreach events, especially those in my lab, the kids are shown how to make the pearls and worms and told why they should not insert the pipet directly into the calcium chloride solution. After the explanation the kids go at it trying to not only make the pearls and worms but challenge each other to see who can make the largest pearl or worm, and the longest worms. Some kids have even adorned themselves with calcium alginate bracelets. I don't use the alginate solution with indicator but I can see how it could be used in a unit about acids and bases, how indicators can be used to distinguish between them. I'll leave it up to those who have to state their reviews. I just see that it could confuse the kids when the concepts of acids, bases, and indicator along with polymers, cross-linking and solubility are addressed at the same time. Since I found the kids enjoy making the pearls and worms, and my use of food coloring to make different colors of alginate solution, and that a large quantity of alginate was being consumed, I now make my own 1% alginate solutions using a blender for non-food usage. Sodium alginate, although is soluble, takes time to dissolve "completely." I make the solution using a blender and then store overnight in a refrigerator, again for non-food use only. I find it to be "completely" dissolved the next day. I divided into four and then add the different food colors to each portion. At Duke we have a course, entitled "The Chemistry of Food," that is taught by a professor whose wife is a culinary chef. The students learn how to make the alginate pearls and the reverse pearls (drops of calcium chloride added to a solution of sodium alginate) using food grade materials that can be consumed. However, even if using food quality materials, I recommend to not allow the kids to consume their work. Several of your more high-end restaurants are including alginate pearls. One medical application that has used the alginate is in bandages, especially for burn victims. The alginate can be made into bandages and applied to the wound. The bandages allow air to flow to the wound necessary for healing and yet can be removed with little to no destruction of the healed tissue. Smaller bandages made with the alginate can be found at drug stores. We use these for kids to see there are applications of calcium alginate besides just fun making them. In any case, this is not only a great kit, but a good way to introduce a number of chemical concepts and applications.
Kenneth Lyle

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5   0

Nice Kit
Review star icon Review star icon Review star icon Review star icon Review star icon Sep 25, 2015
Very well thought out kit. Comes with everything you need - down to the plastic forks! Several lesson ideas are included on a laminated sheet. The kit can be set up for directed group work, but I just made it with the kids in small groups as others were working on another assignment. The kit made a ton - one kit made enough worms for about 36 kids to participate. The "algy" solution has a small amount of cabbage juice in it, so you can also use it for acid/base testing for another activity. I thought for $20 it was well worth it!

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0   0

Fun ingredient for expeiments
Review star icon Review star icon Review star icon Review star icon Review star icon Jul 3, 2014
Making worms and globs of goo is fun no matter what. The cabage juice indicator lets students conduct several pH experiments prior to making the worms and globs of goo. We use this for students to practice experimental design and think about controls, independent, and dependent variables. The only negative that we have encountered is that the shelf life if not listed on the product. We had a bottle degrade after some period of time and not form the polymers in the calcium solution. If you use it fresh--it is a 5!!
Energetic Einsteins

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Amazing worms
Review star icon Review star icon Review star icon Review star icon Review star icon May 24, 2012
Alginate worms are safe and natural. Children in my classroom really enjoyed making them. The best part is that kids can play with wiggly worms!
Elena Kropova

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Review star icon Review star icon Review star icon Review star icon Review star icon May 22, 2012
My Science Club loved this one! Depending on the age of your students you could go into detail on the chemistry behind it or just give them the basics while they enjoy the 'wormy things.'
Cecilia W.

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