True or False: In refraction, when light travels from a more dense medium to a less dense medium, it slows down.

The statement "In refraction, when light travels from a more dense medium to a less dense medium, it slows down" is false. In fact, when light transitions from a denser medium to a less dense medium, it speeds up. This change in speed is due to the differing optical densities of the materials involved, which affects how light propagates through them.

In refraction, the bending of light occurs as it enters mediums with different densities. When moving from more dense to less dense substances, such as from water to air, the light rays will not only speed up but also bend away from the normal line — a line that is perpendicular to the boundary between the two media. This fundamental behavior of light is critical in understanding concepts like lenses, fiber optics, and numerous applications in medical technology and imaging.