Absorbent Water Balls

ABSORBENT WATER BALLS

Scientifically engineered cellulose water balls absorb water and expand to 20 times their original size. Students start out by putting the tiny beads of cellulose in clear plastic cups. They observe them throughout the day and the next day discover that the balls have absorbed the water in the cup and have grown. The balls become jelly- like and are great fun to handle. When the balls have reached their maximum size, children (and adults) love to play with them. Five to ten minutes of ball-time on a smooth table surface is sufficient. Then put them in individual plastic sandwich bags to take home. Parents are often panicked when they see the bag of balls coming home. Their fears are soothed with the suggestion that the balls be put outside to provide moisture to plants; this is also something the children enjoy doing when they get home.

MATERIALS: • Cellulose water balls: available in the plant section of variety stores and online • 9-ounce transparent plastic cups • Re-sealable sandwich bags • Water

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HOW TO: • Put cellulose beads in plastic cups and add water. • Observe and wait 12 hours.

HOW TO PRESENT IT TO YOUR GROUP: 1. Put the cellulose beads in plastic cups: 15-20 per cup is good; yes, the children will be counting to see that it is fair. Write each child’s name on their cup. 2. Pass the cups out and explain that the cellulose beads are going to absorb water and grow, but it will take overnight before they are their full size. Urge students to feel the beads and note how small they are. 3. Fill each cup about 3/4 full of water. 4. Children will observe them for a few minutes. Then you should store them where they can’t be meddled with. 5. The next day, drain any excess water from the cup before giving the cups to the students. 6. Allow the students to observe and play with the jellied balls before putting them in a plastic bag to take home or releasing the balls into the wild (outside where they can water some plants).

THE LESSON: The water balls are made of a very absorbent polymer much like the kind found in disposable diapers. These polymers have amazing absorbency properties because of their ability to fit other molecules (like water) into their structure.

PRESCHOOL SCIENCE VERSION: 5-10 minutes (the first day), 10-20 minutes (the second day) The first day of observing and feeling the tiny beads and then putting them in water only takes 5-10 minutes. The real fun is observing, playing with and squishing some of the balls when they are done the next day. On the first day, divide the children into groups of 4-6. Have members of each group observe the water beads and help to put them in a container of water. About 10-15 beads per child is a wonderful way to have them count the beads into the water container. The second day, the groups will be amazed at the change in the beads and enjoy putting their hands in the container. The children will enjoy the fact that the balls grew and the tactile feel of them. The second-day activity will consist of 10-20 minutes of fun. You can combine all water balls in one large container for a week-long observation or lead the class outside to place the water balls near the base of some plants to see how quickly they release moisture.

VOCABULARY: Molecules, absorbing, polymer, structure