📚 Topic Summary
Dispersion of light is the phenomenon where white light separates into its constituent colors (the spectrum) when passing through a medium like a prism. This happens because the refractive index of the medium varies with the wavelength (color) of light. Shorter wavelengths (like violet) are bent more than longer wavelengths (like red).
Essentially, each color of light travels at a slightly different speed within the medium, leading to their separation. This is why we see rainbows after rain – water droplets act as tiny prisms, dispersing sunlight!
🔑 Part A: Vocabulary
Match the terms with their definitions:
| Term |
Definition |
| 1. Refraction |
A. The spreading of light into its colors |
| 2. Wavelength |
B. The bending of light as it passes from one medium to another |
| 3. Dispersion |
C. Distance between successive crests of a wave |
| 4. Prism |
D. The angle between the normal and the refracted ray |
| 5. Angle of Refraction |
E. A transparent optical element with flat, polished surfaces that refract light. |
Match the letters to the numbers to check your understanding! (Answers: 1-B, 2-C, 3-A, 4-E, 5-D)
✍️ Part B: Fill in the Blanks
Complete the following paragraph using the words: wavelength, refractive index, prism, dispersion, violet, red.
The phenomenon of ________ occurs when white light passes through a ________. This happens because the ________ of the medium varies with the ________ of light. ________ light bends more than ________ light because of this variation.
(Answers: dispersion, prism, refractive index, wavelength, violet, red)
🤔 Part C: Critical Thinking
Why does dispersion not occur when light travels through a vacuum?