Refraction:
* The light bends away from the normal. This means the angle of refraction (the angle between the refracted ray and the normal) is greater than the angle of incidence (the angle between the incident ray and the normal).
* The speed of light increases. This is because the speed of light is inversely proportional to the refractive index of the medium. Since the second medium has a lower refractive index, the speed of light increases.
Other Phenomena:
* Total Internal Reflection: If the angle of incidence is greater than a critical angle, all of the light is reflected back into the first medium. This is because the angle of refraction would be greater than 90 degrees, which is not possible.
* Change in Wavelength: The wavelength of light also changes as it passes from one medium to another. The wavelength in the second medium is longer than the wavelength in the first medium.
Example:
Imagine a light ray traveling from water (higher refractive index, slower speed of light) to air (lower refractive index, faster speed of light). As the light ray enters the air, it will bend away from the normal, and its speed will increase.
Key Concept:
The phenomenon described above is known as refraction and is governed by Snell's Law:
```
n1 * sin(θ1) = n2 * sin(θ2)
```
where:
* n1 and n2 are the refractive indices of the first and second media, respectively
* θ1 and θ2 are the angles of incidence and refraction, respectively
This law explains the relationship between the angle of incidence, angle of refraction, and the refractive indices of the two materials.
