Water Science Experiments

Looking for some simple science experiments for your elementary school child? These two deal with the process of osmosis using simple ingredients and directions.

Osmosis Gummy Bear

You will need a small cup of water, a gummy bear, and a ruler. Results will be measurable in 24 hours.

First, make a prediction about what you think will happen when you leave a gummy bear in water overnight. The steps we take to see if a prediction is accurate are called an experiment.

Do you think the gummy bear will get bigger, the gummy bear will get smaller, or the gummy bear will stay the same size?

To complete the experiment, first take measurements of the length and width of your gummy bear. Trace around your gummy bear on a piece of paper. Now, put the gummy bear in the cup. Fill with just enough water to cover up the gummy bear and let it soak in the water overnight. In the morning, check the length and width of your gummy bear. Draw an outline of it on the same piece of paper you used earlier to compare results.

Osmosis causes the gummy bear to grow bigger because it soaks up water. Water moves from areas that have large water content to areas that have less water. Osmosis balances the wet and dry areas so the water content is more equal between the two areas. A gummy bear doesn't contain much water. Placing a dry gummy bear into a bowl of water attracts water and grows as it holds more and more water.

Baking Soda String

What do you think will happen when water being moved by osmosis has something else dissolved or mixed into it?

To find out, you will need 12 inches of cotton string, baking soda, 2 plastic cups, water, and a tablespoon. To see results takes 2 days.

First, fill the plastic cups with water. Add 1 tablespoon of baking soda into each cup. Using the 12 inch string, place one end in one cup and the other end of the string in the other cup. Leave the experiment alone for two days. Do not do anything to the cups while you are waiting. After two days, draw a picture of what the string looked like before and after the experiment.

Because the string is drier, the water is attracted to it. Since the baking soda is dissolved in the water, it is attracted to the string as well, inching up the string. Small clumps or spikes are formed.