 Saha ionization equation

Chemical equilibrium for $A^{+}+e^{-}\leftrightarrow A^0+\gamma$ givesafter neglecting the ion--atom mass difference in the translational prefactor.

The Saha ionization equation is a mathematical formula that describes the ratio of the number densities of ions to neutral atoms in a thermal equilibrium state, particularly in astrophysical contexts such as stellar atmospheres. It is useful for understanding how ionization states of elements vary with temperature and electron pressure.