What happens to light when it passes into a different medium?

• A. It changes direction when entering a new medium
• B. It remains straight with no change
• C. It reflects off the surface only
• D. It changes color but not direction

Answer: (A)

Refraction is what happens when light moves from one medium into another. The speed of light is different in each material, so when the boundary is crossed, the light changes speed and that change makes its path bend. This bending explains everyday observations like a pencil appearing tilted in a glass of water. If the new medium is denser (slower light), the light bends toward the normal; if it’s less dense (faster light), it bends away from the normal. In general, crossing into a different medium changes the direction of light, which is why this option is the best description.