One activity that can visually demonstrate that white light is made up of seven colors is the rainbow experiment. Here's how you can do it:
Materials needed:
- A glass prism
- A white light source (e.g., flashlight)
- A dark room
Instructions:
- Set up the experiment in a dark room where you can control the lighting.
- Position the prism on a flat surface, such as a table or a stand, ensuring it is stable and stationary.
- Turn on the white light source, such as a flashlight.
- Direct the beam of white light towards the prism.
- Observe the light passing through the prism and onto a wall or a white surface.
- You should see a beautiful band of colors projected on the wall opposite the prism. This is called a spectrum.
- The spectrum will typically display the following colors from top to bottom: red, orange, yellow, green, blue, indigo, and violet. This sequence of colors represents the seven colors that make up white light.
By passing white light through the prism, the light is refracted (bent) as it enters and exits the prism due to the variation in the refractive index for each color. This causes the different colors to spread out, creating the visible spectrum.
The rainbow experiment effectively demonstrates that white light is composed of different colors and helps visualize the phenomenon of dispersion.