* Frequency is a property of the source: The frequency of light is determined by the vibration of the source that emits it (like an atom or molecule). Think of it like a tuning fork – it always vibrates at the same frequency, regardless of what medium it's placed in.
* Refraction is about speed change: When light enters a different medium, it interacts with the atoms in that medium. This interaction causes the light to slow down (or speed up), which changes its velocity.
* Wavelength adjusts: To maintain the fundamental relationship between frequency, wavelength, and speed (speed = frequency x wavelength), the wavelength of light changes during refraction. If the speed decreases, the wavelength must shorten to compensate.
Analogy: Imagine you're walking through a crowded room. Your steps (frequency) remain the same, but you have to take smaller steps (wavelength) because you're moving slower.
Key Point: The frequency of light is a fundamental property and doesn't change when it enters a new medium. It's the wavelength that adjusts to accommodate the speed change.
