A light spectrum experiment typically involves using a prism to separate white light into its constituent colors, demonstrating the full spectrum of visible light.
This classic experiment reveals the composition of white light and how different wavelengths correspond to different colors. Here's a breakdown of the process:
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Materials: The primary component is a prism, typically made of glass or acrylic. A source of white light, such as sunlight or a bright lamp, is also needed.
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Procedure:
- Setup: Position the prism in the path of the white light beam.
- Refraction: As the white light enters the prism, it slows down and bends (refracts).
- Dispersion: Because different wavelengths of light bend at slightly different angles, the white light separates into its individual colors. This phenomenon is called dispersion.
- Observation: The separated colors, forming a spectrum (red, orange, yellow, green, blue, indigo, violet), are projected onto a surface, like a white wall or screen.
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Result: The experiment clearly demonstrates that white light isn't a single color, but a mixture of all the colors of the visible spectrum. Each color corresponds to a specific wavelength of light. Red has the longest wavelength, and violet has the shortest.
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Why it works: The speed of light changes when it passes from one medium (air) to another (glass). This change in speed causes the light to bend. The amount of bending depends on the wavelength of the light, causing different colors to separate.
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Variations: While a prism is the most common tool, other methods can demonstrate light spectra, such as using diffraction gratings or even observing rainbows (natural light dispersion through water droplets).
