In nuclear physics, the semi-empirical mass formula (SEMF) (sometimes also called Weizsäcker's formula, or the Bethe-Weizsäcker formula, or the Bethe-Weizsäcker mass formula to distinguish it from the Bethe–Weizsäcker process) is used to approximate the mass and various other properties of an atomic nucleus. As the name suggests, it is based partly on theory and partly on empirical measurements. The theory is based on the liquid drop model proposed by George Gamow, which can account for most of the terms in the formula and gives rough estimates for the values of the coefficients. It was first formulated in 1935 by German physicist Carl Friedrich von Weizsäcker, and although refinements have been made to the coefficients over the years, the structure of the formula remains the same today.
The SEMF gives a good approximation for atomic masses and several other effects, but does not explain the appearance of magic numbers of protons and neutrons, and the extra binding-energy and measure of stability that are associated with these numbers of nucleons.
Read more about Semi-empirical Mass Formula: The Liquid Drop Model and Its Analysis, The Formula, Calculating The Coefficients, Examples For Consequences of The Formula
Famous quotes containing the words mass and/or formula:
“They’re semiotic phantoms, bits of deep cultural imagery that have split off and taken on a life of their own, like those Jules Verne airships that those old Kansas farmers were always seeing.... Semiotic ghosts. Fragments of the Mass Dream, whirling past in the wind of my passage.”
—William Gibson (b. 1948)
“The formula for achieving a successful relationship is simple: you should treat all disasters as if they were trivialities but never treat a triviality as if it were a disaster.”
—Quentin Crisp (b. 1908)