Final answer:
Light bends toward the normal when entering a medium with a higher refractive index because the speed of light is reduced, causing the light ray to change direction according to Snell's Law.
Step-by-step explanation:
The refraction of light occurs when a ray of light passes from one medium to another with a different refractive index. The refractive index is a measure of how much the speed of light is reduced inside a medium compared to its speed in a vacuum. Refraction is governed by Snell's Law, which states that the ratio of the sine of the angle of incidence to the sine of the angle of refraction is constant, depending on the two media's refractive indices.
When a light ray enters a medium with a higher refractive index, it slows down and bends toward the normal—a line perpendicular to the boundary between the two media. Conversely, when it enters a medium with a lower refractive index, it speeds up and bends away from the normal. This concept is often illustrated by the analogy of a lawn mower moving from a path (where it moves faster) onto grass (where it moves slower), causing it to turn towards the grass.