A special form of scattering that occurs when the structures dimensions are much smaller than the beam’s wavelength.

• A. Mie scattering
• B. Rayleigh scattering
• C. Raleigh scattering
• D. Compton scattering

Answer: (B)

The key idea here is the Rayleigh scattering regime: when the structures are much smaller than the wavelength, each particle behaves like a tiny dipole driven by the incoming wave. The scattered field from these dipoles adds up in a way that makes the scattering highly sensitive to wavelength. Specifically, the scattering cross-section scales as (d/λ)^6 and the intensity goes roughly as 1/λ^4, so shorter wavelengths scatter much more strongly than longer ones. This is why, for example, atmospheric molecules produce a blue sky—the shorter wavelengths are scattered in all directions while the colors with longer wavelengths pass through more readily.

The best term for this situation is Rayleigh scattering. Other options describe different scenarios: Mie scattering happens when particle sizes are comparable to the wavelength, leading to different angular patterns; Compton scattering is a quantum process of photons scattering off free electrons and is not about small-particle size relative to wavelength; a misspelled form is not the standard terminology.