The science of scattering by particles is very hard. This app, plus the Rayleigh one, provide two idealised cases that at least provide some guidance about the effects of particle sizes and refractive indices.
Here we have a higher (less unrealistic) concentration of particles and see how much scattering there is for any given particle size at our chosen wavelength, λ, and refractive indices of the medium and the particle..
Scattering from surfaces is discussed in the Gloss app.
With more concentrated and larger, but still relatively isolated particles, Rayleigh scattering is not a good-enough approximation and the next level up is Mie scattering. The theory is too complex for a typical app, but the van de Hulst approximation does a reasonable job - and besides, most real-world situations are too complex for Mie anyway.
Just enter the refractive index, n, of the medium and the particle, and the wavelength of choice and the scattering from particles of different radii is shown.