* No refraction: The light ray continues to travel in a straight line, without bending. This is because the angle of incidence (the angle between the incident ray and the normal to the interface) is 0 degrees, and Snell's Law dictates that the angle of refraction will also be 0 degrees.
* Partial reflection: Even though the light doesn't bend, a portion of it is reflected back into the first medium. The amount of reflection depends on the refractive indices of the two media.
* Transmission: The remaining portion of the light ray passes through the interface into the second medium.
In summary:
* No change in direction.
* Partial reflection.
* Partial transmission.
Example:
Imagine shining a flashlight directly onto a glass window. The light goes straight through the window, but a faint reflection is also visible on the glass surface.
