What phenomenon describes the scattering of light?

The phenomenon that describes the scattering of light is diffusion. Diffusion occurs when light interacts with particles or irregularities in a medium, causing it to spread out in many different directions. This scattering effect can be observed, for example, when light passes through fog or when it encounters an object that is not smooth, resulting in a softer appearance of the light rather than a defined beam.

Refraction involves the bending of light as it passes from one medium to another, changing speed due to different optical densities. Diffraction refers to the bending of light around obstacles and the spreading of light waves when they pass through small openings. Reflection describes the bouncing back of light when it hits a reflective surface. Thus, while all these terms relate to the behavior of light, diffusion specifically pertains to how light scatters in various directions, making it the correct answer.