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Electron affinity can be defined in two equivalent ways. First, as the energy that is released by adding an electron to an isolated gaseous atom. The second (reverse) definition is that electron affinity is the energy required to remove an electron from a singly charged gaseous negative ion.
In any case, the value of the electron affinity of a solid substance is very different from the chemistry and atomic physics electron affinity value for an atom of the same substance in gas phase. For example, a silicon crystal surface has electron affinity 4.05 eV, whereas an isolated silicon atom has electron affinity 1.39 eV.
The electron affinity (usually given by the symbol in solid state physics) gives the energy difference between the lower edge of the conduction band and the vacuum level of the semiconductor. The band gap (usually given the symbol E g {\displaystyle E_{\rm {g}}} ) gives the energy difference between the lower edge of the conduction band and the ...
One can test for a bromide ion by adding an oxidizer. One method uses dilute HNO 3. Balard and Löwig's method can be used to extract bromine from seawater and certain brines. For samples testing for sufficient bromide concentration, addition of chlorine produces bromine (Br 2): [7] Cl 2 + 2 Br − → 2 Cl − + Br 2
The energy required to remove one or more electrons to make a cation is a sum of successive ionization energies; for example, the energy needed to form Mg 2+ is the ionization energy required to remove the first electron from Mg, plus the ionization energy required to remove the second electron from Mg +. Electron affinity is defined as the ...
In this way, the electrons of an atom or ion form the most stable electron configuration possible. An example is the configuration 1s 2 2s 2 2p 6 3s 2 3p 3 for the phosphorus atom, meaning that the 1s subshell has 2 electrons, the 2s subshell has 2 electrons, the 2p subshell has 6 electrons, and so on.
An amount of 0.35 from each other electron within the same group except for the [1s] group, where the other electron contributes only 0.30. If the group is of the [ns, np] type, an amount of 0.85 from each electron with principal quantum number (n–1), and an amount of 1.00 for each electron with principal quantum number (n–2) or less.
For example, the electron binding energy for removing a 3p 3/2 electron from the chloride ion is the minimum amount of energy required to remove an electron from the chlorine atom when it has a charge of −1. In this particular example, the electron binding energy has the same magnitude as the electron affinity for the