good friend 發問時間: 科學化學 · 2 0 年前







那麼矽的N型和P型哪種被定義出的電負度應較大呢?與是N型或P型有關嗎( 假設雜質與矽的半化合狀態很穩固不能被分解)?

1 個解答

  • 延德
    Lv 6
    2 0 年前

    依照 IUPAC (International Union of Pure and Applied Chemistry 國際純粹和應用化學聯合會) 的定義, 電負度的定義只限於原子. 我想你一定聽過 IUPAC 但是或許不了解它的功能及地位, 簡單來說它就是化學界的老大, 所有標準的命名,定義,規定以及其他種種化學相關的東西,任何資料都是以他所公佈的為準. 所以1,2題的答案都是"不可以", 第3題則是"無從比較起, 因為根本沒有電負度可比"附上 IUPAC 對電負度 Electronegativity 的定義供您參考:Electronegativity - The power of an atom in a molecule to attract electrons. The two widespread empirical scales of electronegativity are those developed by L. Pauling and R. Mulliken. The Pauling scale is thermochemical; it is based on the values of bond energies of type X-Y, X-X and Y-Y molecules from which the ionic contribution to the X-Y bond is defined as DXY = EXY - (1/2)(EXX + EYY) From this value the relative electronegativity of X with respect to Y is defined (in eV1/2 units) as cX - cY  (DXY)1/2The Mulliken electronegativity ( in eV units) is given by the equation: cX = (1/2) (IX + AX) where IX and AX are respectively ionization potential and electron affinity in a suitable valence state (see valence state ionization potential, valence state electron affinity). both scales are linearly interrelated. These are useful for estimating bond polarities and strengths of bonds between different atoms. Many other scales of electronegativity are known, among which that of A. Allred and E. Rochow , where electronegativity is defined as the electrostatic force between the nucleus and its valence electrons, is most frequently used. Accounting for the observation that the position of bond points relates to the polarity of a bond, a scale of atomic and group electronegativities, which are comparable in magnitude to the Pauling values, was derived (R. Boyd) on the basis of topological properties of the electron density distributions in model hydrides R-H. ALLEN (1994); ALLRED and ROCHOW (1958); BERGMANN and HINZE (1996); BOYD and BOYD (1992); MULLIKEN (1934); PAULING (1932).