Which example best illustrates light behaving like particles?

• A. Light bends as it strikes a window.
• B. Light travels in straight lines.
• C. Light bounces off a white cement sidewalk.
• D. Light travels faster in a vacuum.

Answer: (C)

The example of light bouncing off a white cement sidewalk best illustrates light behaving like particles due to the principle of reflection. When light encounters a surface, such as that of the sidewalk, it can be thought of as a collection of particles (or photons) that interact with the surface.

This interaction demonstrates particle behavior because, like balls bouncing off a hard surface, photons can be reflected at an angle equal to the angle at which they strike the surface (known as the law of reflection). This concept aligns well with the particle model of light, where light is viewed as discrete packets of energy that can collide with surfaces, thereby changing direction.

In contrast, the bending of light as it strikes a window and the travel of light in straight lines reflect wave properties of light, while the idea of light traveling faster in a vacuum is related to its wave-like characteristics as well. These phenomena do not capture the particle aspect of light in the same way that reflection does.