Any colloidal species containing a radionuclide. Somewhat of a misnomer in that colloidal properties derive from the nature of atoms and molecules rather than from nuclei.

Radiometric Forces

See Phoretic Forces.


The phase that remains after specified solute(s) has been removed by extraction. Note that this meaning is distinct from the original meaning of raffinate as a refined product.

Rag Layer Emulsion

See Interface Emulsion.


A rain cloud is an aerosol of liquid droplets. See Aerosol of Liquid Droplets, and Table 8.

Raman Effect

See Raman Scattering.

Raman Scattering

When light is scattered from a solid, some components of the scattered light have a shifted frequency due to energy gains or losses when atoms or molecules change vibrational or rotational motions. The Raman frequency is the difference between the frequency of scattered and incident light and gives the vibrational frequency of the bond responsible for the scattering.

Raman Spectroscopy

The use of Raman scattering to identify functional groups and bonding in a solid sample.

Random Copolymer

A copolymer in which the constituent monomer molecules are randomly arranged in the polymer backbone. See also Block Copolymer.

Rapid Aggregation

See Perikinetic Aggregation.

Rayleigh–Gans–Debye Scattering

A modified model of Rayleigh scattering. See also Light Scattering.

Rayleigh Instability

See Rayleigh–Taylor Instability.

Rayleigh, Lord

See Strutt, John William (1842–1919) ...

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