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The debye (symbol: D) (;〔''Random House Dictionary'', Random House, 2013: "Debye".〕 ) is a CGS unit〔(CGS units ) R. Rowlett (University of North Carolina at Chapel Hill)〕 (a non-SI metric unit) of electric dipole moment〔Electric dipole moment is defined as charge times displacement: :''p'' = ''qr''〕 named in honour of the physicist Peter J. W. Debye. It is defined as 1 statcoulomb-centimetre.〔The statcoulomb is also known as the franklin or electrostatic unit of charge. :〕 Historically the debye was defined as the dipole moment resulting from two charges of opposite sign but an equal magnitude of 10−10 statcoulomb〔10−10 statcoulomb is approximately 0.2083 units of elementary charge.〕 (generally called e.s.u. (electrostatic unit) in older literature), which were separated by 1 ångström.〔The ångström is of an order of magnitude close to that of a typical covalent bond. :〕 This gave a convenient unit for molecular dipole moments. : Typical dipole moments for simple diatomic molecules are in the range of 0 to 11 D. Symmetric homoatomic species, e.g. chlorine, Cl2, have zero dipole moment and highly ionic molecular species have a very large dipole moment, e.g. gas phase potassium bromide, KBr, with a dipole moment of 10.5 D.〔''Physical chemistry'' 2d Edition (1966) G.M. Barrow McGraw Hill〕 The debye is still used in atomic physics and chemistry because SI units are inconveniently large. The smallest SI unit of electric dipole moment is the yoctocoulomb-metre, which is roughly 300,000 D.〔Yocto-, with a value of 10−24, is the smallest SI prefix. Note that SI disallows the application of prefixes to both members of a compound unit or the compounding of prefixes, thus ruling out such units as the femtocoulomb-femtometre or the microyoctocoulomb-metre (both approximately 0.3 D) respectively.〕 There is currently no satisfactory solution to this problem of notation without resorting to the use of scientific notation. ==See also== Buckingham (unit) (CGS unit of electric quadrupole) 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Debye」の詳細全文を読む スポンサード リンク
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