If light passes from air into water and changes direction, which term applies?

If light passes from air into water and changes direction, which term applies?

• A. Reflect
• B. Refract
• C. Scatter
• D. Solar

Answer: (B)

Refraction is the bending of light as it passes from one medium into another with a different optical density. When light moves from air into water, it slows down because water has a higher refractive index, so its path tilts toward the normal to the boundary, causing a change in direction. This behavior is described by Snell’s law, relating the angles of incidence and refraction to the indices of the two media. This is distinct from reflection, where light bounces off the surface instead of entering the new medium, and from scattering, where light is dispersed in many directions by rough surfaces or particles. Solar isn’t relevant to this boundary-driven change of direction.

Refraction is the bending of light as it passes from one medium into another with a different optical density. When light moves from air into water, it slows down because water has a higher refractive index, so its path tilts toward the normal to the boundary, causing a change in direction. This behavior is described by Snell’s law, relating the angles of incidence and refraction to the indices of the two media. This is distinct from reflection, where light bounces off the surface instead of entering the new medium, and from scattering, where light is dispersed in many directions by rough surfaces or particles. Solar isn’t relevant to this boundary-driven change of direction.