Black Body

n The theory that atoms can exist for a duration solely in certain states, characterized by definite electronic orbits, i.e., by definite energy levels of their extranuclear electrons, and in these stationary states they do not emit radiation; the jump of an electron from an orbit to another of a smaller radius is accompanied by monochromatic radiation. A black body has an emissivity (e _B) of 1, indicating that a black body absorbs then emits all radiation at a wavelength. A black body is the opposite property of a perfect reflector of radiation at a wavelength that absorbs no radiation. (Odian GC, (2004) Principles of polymerization, Wiley, New York).