Simple Science Experiments for the Early Childhood Classroom
By Jon Keil

Teaching simple science is the art of taking a big idea and explaining it in an age-appropriate manner using easy, practical, and fun experiments. With all the demands on the early classroom teacher, the emphasis is on "easy". This article contains a number of simple science experiments for the young children in your program. Let's start with water.

States of Matter
One of the "big ideas" behind the simple science of water is that water is matter, and matter is any physical thing that takes up space. Water is significant because it is the only matter that exists naturally in all three states: solid, liquid, and gas.

Here is an easy way to demonstrate properties of matter. In a plastic lined table, place a bag of ice or snow. Explain to the children that this is water in a solid form. Place some trucks, dinosaurs, and other toys in the ice and snow to give the tactile learners a chance to play with the water and grasp the concept.

As the ice melts, ask the children, "Where did all this water come from?" Then explain the science behind melting. The movement of molecules causes snow to melt. In a solid form, the water molecules move very slowly. They move faster in a liquid form and still faster as the water changes to steam or vapor. With small children, it is best not to heat water and show steam. However, you can demonstrate water as a gas by cleaning up the mess made while doing the ice experiment with cloth towels. Hang the wet towels over easels or picture racks. When the students return the next day ask them to examine the towels. Encourage them to think about how the water disappeared from the towels. You can then explain that as the molecules moved faster and faster, some of them escaped into the air, which in turn dried the towels.

To further demonstrate evaporation, try this simple science experiment. Fill two identical jars half full of water. Measure and mark the levels on the outside of both jars. Cover one of the jars with aluminum foil. Place both jars in the sun and wait for several days and observe. Encourage the children to think about why the jar with foil over it has more water. Answer: The foil covering the top of the jar kept the water from evaporating. Observe the jars over a period of a few days or weeks. The children can record the rate of evaporation by measuring the water in the jar each day and keeping a log.

You can also demonstrate the opposite of evaporation - condensation - by taking a very cold glass of water and placing it on a table. Within a few minutes, water droplets will form on the outside of the glass. Ask the children, "Where did the water come from? Did it leak out of the glass?" The answer is that air, which is laden with water vapor, comes in contact with the glass. This causes some of the water molecules to slow down and attach themselves to the glass. You can tie all of these experiments together by explaining that the same water molecules that disappeared from the cleanup towels in the first water experiment are now reappearing on the outside of the water glass.

Pressure
Another fun property to explore with water is pressure. Begin teaching the concept of pressure by explaining to the children that water is heavy! Take an empty gallon plastic milk jug and fill it with water, then have the students attempt to pick it up. After all the grunts and groans, have them put it on a bathroom scale to get a rough idea of the actual weight. Now comes the fun part!

Take an empty plastic two-liter soda bottle. Drill or punch three holes in the side of the bottle, one at the very bottom, one in the middle, and another closer to the top. Using a plastic lined table, fill the bottle with water while on its side with the holes up. Stand the bottle upright and observe the streams of water. While observing the water stream from the bottle ask the children, "Why are the streams of water different lengths?" The students have already discovered that water has weight. Now they are observing the water's weight at work. Water, like all matter, is pulled toward the center of the earth by the force called gravity. This action creates pressure. The water stream at the bottom of the bottle is pushed out by the weight of the water above it. The students will observe that the longest stream is at the bottom hole and the shortest is at the top.

Sinkers and Floaters
With a table full of water, have the children select several objects from the classroom to be placed in the water (corks, sponges, toy cars, etc). Then have the children guess which objects will float and which ones will sink. As the children place the objects in the water, ask them to guess why some things float and other things sink. The science concepts to be learned from this experiment are density and displacement. Water will try to support solid objects. The easy way to explain density is that objects that are heavy for their size tend to sink, while objects that are light for their size tend to float. The exception occurs when the shape of the object (its displacement) determines if it will sink or float. Try the following experiment to explain density and displacement in another way. For this experiment you will need two pieces of bread. First, put a full slice of bread on the surface of the water and observe that the bread floats (at least until it gets water logged). Next, make small balls out of the other piece of bread and watch as they sink. This simple experiment shows that the shape of the object will determine the displacement of the water and whether something made out of the same material will sink or float.

Record Your Observations
When doing "simple science" keep a notebook or chart to write down observations made by the children. When beginning any science experiment, ask the children what they think is going to happen. Record the children's ideas, measure the children's actions while doing the experiment, and compare the results. It is amazing how often the children already know what the results will be. Of course the value of doing the experiment is to validate and quantify what many of them have already observed. After finishing the experiment review the chart with the children to show what they have learned.

Conclusion
The possible areas of study for simple science are as varied as the world around us. Air, light, plants, animals, and magnets are just a few. The concepts can be complex, but the simple examples are at our fingertips. Children are curious creatures. They want to know how things work and why things happen. They are willing participants in art of teaching simple science. And why not? Science is fun!

Jon Keil home schools his two sons in Monterey, CA.