Electron gain energy

As energy is added and photons collide with other atoms, more and more electrons gain energy and jump orbits. The excited atoms all emit photons at the exact same wavelength. At some point there are more atoms with electrons in excited states than at ground level. This is population inversion. 

Electron Gain Energy, Electron Gain Enthalpy and Electron Affinity... 

The standard molar energy change associated with the attachment of an electron to an atom or ion according to equation 2.3 is its electron gain energy, It is perhaps surprising to find that the first values for some transition metals are comparable to those of non-metallic elements. 

Table 2.6 Electron gain energies (P) and electronegativities (x) of the transition elements...

Electron gain energies (P in kJ mol ) are shown in italic text and are taken from Hotop and Lineburger or Bratsch and Lagowski . 

A plasma is a partially ionized gas composed of ions, electrons and neutral species. It is a state of matter that can be created by such diverse techniques as flames, electrical discharges, electron beams, lasers or nuclear fusion. The technique of most interest to plasma polymerization is the glow discharge, in which free electrons gain energy from an imposed electrical field, and subsequently loses it through collisions with neutral molecules in the gas. The transfer of energy to gas molecules leads to the formation of a host of chemically reactive species, some of which become precursors to the plasma polymerization reaction. 

Due to their lower mass the electrons gain energy far more rapidly and then undergo inelastic collisions. At each inelastic collision the number of electrons increases by a factor of 2. If the average number of collisions is n the amplification factor is 2" an avalanche initiated by one electron thus consists of 2" final ion pairs. The output pulse heights are proportional to the incident photon energy. 

This chapter deals with the variations, across the periods and down the groups of the Periodic Table, of (i) the ionization energies, (ii) electron attachment energies (alternatively known as electron gain energies and electron affinities), (iii) atomic sizes and (iv) electronegativity coefficients of the elements. The influence of relativistic effects is introduced. 

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