Science Projects for Kids – Easy Experiments With Light

Sep 10, 2010
Carol Wells

Science fun with a homemade projector - Photo by Carol Wells

Scientists still have much to learn about light, but you can learn some "enlightening" things by performing a few easy science experiments.

What is light? Is it a particle? Is it a wave? Is it a combination of both? Or is it something else altogether? Scientists who study light admit that they don't know everything there is to know about light. But whatever light is, we're very lucky that it exists: light is what enables the human eye to see.

Scientists do know how light reacts under certain conditions. Three reactions of light are demonstrated in the following science experiments for kids. See the images following this article for illustrations of the experiments. Click on an image to enlarge it.

Light Reflection – Make a Disappearing Penny Reappear

Experiment:

Place a penny in the center of a small opaque (you can't see through it) shallow bowl.
Set the bowl on a table or counter top in a well-lit room.
Ask a friend to keep an eye on the penny as he slowly backs away from the bowl.
Tell your friend to stop as soon as the edge of the bowl just blocks his view of the penny.
Now tell him you will magically make the penny reappear.
Slowly fill the bowl with water without disturbing the penny.
Does your friend see the penny come back into view?

Observation: After a sufficient amount of water is added to the bowl, your friend says he can see the penny.

Explanation: As water fills the bowl, the reflection of the penny bends around the bowl to the surface of the water, making your friend think that he can see the penny again.

Light Refraction – Make a Simple Magnifying Glass

Experiment:

Place a clear round jar or drinking glass close to the ingredients list on a cereal box.
Look through the jar at the printing.
Are the words easy to read?
Now fill the jar with water and place it close to the ingredients list again.
Are the words easier to read?

Observation: When the jar contains water, the printing on the cereal box appears much larger.

Explanation: As light enters the curved jar, its course is altered or bent by the water. This bending, or refraction of the light, results in your homemade magnifying glass.

Light Diffusion – Make a Simple Light Projector

Items needed:

construction paper in five colors
five round items to use as patterns (see Preparation below)
pencil
children's scissors
glue stick
shoebox with a lid
ruler
sharp scissors or utility knife and an adult's assistance
flashlight

Preparation:

Cut five circles from different colors of construction paper in the following diameters: 3 inch, 5 inch, 7 inch, 9 inch, 11 inch. Sizes are approximate. Use round items that you have on hand for patterns. You might need to tape two pieces of paper together for the largest circle.
Glue the 3-inch circle to the 5-inch circle, the 5-inch to the 7-inch, the 7-inch to the 9-inch, and the 9-inch to the 11-inch.
Measure and draw a one-inch square in the center of each small end of the shoebox.
Ask an adult to carefully cut the squares out with the scissors or utility knife.
Place the lid on the shoebox.
Dim the lights in the room where your experiment will take place.

Experiment:

Ask a friend to hold the construction-paper target in front of you.
Hold the shoebox about one foot away from the target.
Shine a flashlight through the holes in the shoebox so the light falls directly on the center of your target.
Ask your friend to gradually move the target away from the shoebox.
What happens to the light as the target is moved?

Observation: As the light source becomes farther away from the target, the light spreads over more of the target's surface and its brightness becomes dimmer.

Explanation: The beam of light is strongest and brightest inside the shoebox. Once it passes out of the box, the light begins to spread out in straight lines to fill the larger area. Some of the light rays reflect or bounce off the paper target and scatter around the room. This scattering of light is called diffusion.