Ionization energy is defined as the energy required to remove an electron from a gaseous atom. For example, 8.64 × 1 0 -19 J is required to remove an electron from a gaseous lithium atom. The energy …

It is customary to express the ionization energy in electron volts, 1 eV = 1.602 × 10−12 erg. Ionization of the most abundant elements, hydrogen and helium, is important for the equation of state.

The degree of ionization depends on temperature. A general relation between the degree of ionization and temperature can be obtained from a statistical description of plasma in thermodynamic equilibrium.

It lists the sources of data on ionization energies and electron afinities available in the literature. The reliability and accuracy of measured and calculated values are discussed. Principal applications of …

Figure 13-3 Electron ionization accompanied by different degree of excitation of the molecular ion. Soft ionizing events transfer excess energy to the ionized molecule, which is observed.

This is the Saha Equation, derived in 1920, which describes the detailed balance between ionization states; it connects to processes like collisional ionization, the photoelectric e ect, and recombination.

Figure 1: The ionization fraction x of a pure hydrogen gas, plotted as a function of temperature.