Science Experiments For Children

By Richard Bourbeau

Summer is finally here and with its arrival comes a great opportunity for outdoor exploration! The seashore is not just a fantastic place for recreation, it also serves as an ideal forum for satisfying your child's thirst for knowledge-about the world.

While science kits, books and computer software are sufficient as educational tools they cannot act as substitutes for the hands on experiences that are needed to stimulate a child's interests in the material sciences. They are also expensive.

You need not spend a lot of money to spark your child's interests in and increase his grades in science. It is important, however, that you devote enough time to research the project or topic thoroughly before beginning the venture.

Remember that important discoveries rarely occur quickly, and the questioning and classification process of the scientific should not be rushed. Finding interesting topics that don't require a lot of money and which don't take a lot of time should not be difficult since there are few pleasures greater than a nature walk with your child and watching a natural scientist at work.

It may be helpful for you to consult a field guide to enhance your knowledge. Most large parks and seaside reserves in and outside of New York City have free field guides that list entertaining and educational attractions. The guides also provide suggestions for follow up experiments and activities. The State's Parks Department provides these guides at visitor's centers or by calling the numbers in the "blue" section of the phonebook. Researching a topic is especially important if you are the parent of older children who, quite naturally, want to cover topics in greater depth. Perhaps you and your child can choose and research the topic together as a preliminary activity.

For all children, it is important to encourage them to use their senses to learn about nature. Magnifying glasses, binoculars and nets are helpful, but not necessary. Cameras and notebooks allow children to make permanent records of their experiences.

TIDES

Before going to the beach, ask your child what he or she expects to see in order to help the child prepare. It may be helpful to discuss tides and offer an initial, simple explanation of how sand is formed as preparation.

To explain tides, start off by having your child hold two magnets and by gradually moving them closer together until they can feel the force pulling them together. Next, use a grapefruit, an orange and a cherry (or other round objects of different sizes) to represent the Sun, the Earth, and the Moon. Explain that these have an attraction to one another like the magnets do. These attractions pull water underneath the moon up toward it, creating a bulge which appears to us as a large, moving wave. At the opposite end of the earth, the centrifugal force from the Earth's rotation causes a second bulge. High tide occurs when a bulge hits land. Between bulges, low tide occurs.

The following experiment can show the effect of centrifugal force on tides:

Materials: ruler, scissors, paper drinking cup, string, pencil

Procedure:

Results should showthat centrifugal force holds the water inside the spinning cup. Tides work on the same principle.

SAND

Explain that sand is formed from rock by the weathering action of wind and water. The following experiment can be performed at home to demonstrate this process:

Materials: writing paper, pencil with eraser

Procedure:

Results show the removal of pencil graphite from the paper and particles of eraser left on the paper. Graphite is found in many rocks. Erasers are made of high-friction materials. The process is similar to the way that sand, blowing over the rocks, creates friction and acts like an eraser by removing bits of rock. Over time, as more rock gets rubbed away, only sand is left.

Upon arrival at the shore, let children look at the sand. They can use a magnifying glass and see how many colors and shapes they can see in the sand.

You can bring a magnet and run it through the sand. You should end up with particles sticking to the magnet. Ask your child why this has happened and suggest that particles must be made of iron or steel.

WAVES

Encourage your child to look at the waves rolling back and forth, and ask them if they know what causes the waves. Explain that the waves commonly seen on the shore are wind waves caused by the friction of the wind blowing across the water.

The size of waves depends on the distance the wind travels over a wave, the strength of the wind, and the length of time the wind blows. As a follow up, when you get home you can demonstrate how waves move across the water with the following experiment:

Materials: Book, marbles

Procedure:

Results show that as the free marble strikes the group of marbles, it stops, and the marble at the opposite end of the group moves forward. What occurred, was a transfer of energy from the free marble to each successive marble. This same type of energy transfer occurs in the ocean until the shoreline is reached, resulting in water movement.

Richard Bourbeau is a science teacher for the New York City Board of Education whose team has won grants for their science programs. He is also the owner and director of the A-Plus Center for Learning, a service offering tutorials, after-school and summer programs. He can be reached at 212-921-2420.