“The temperature at which the concentration of singly ionized atoms reaches a maximum is given by[372]
The two formulae that have been quoted assume, in effect, that at any stage of ionization the number of atoms, in stages other than those whose constants appear in the formulae, is negligible. When two ionizations occur in very close succession, this assumption no longer holds, and the equations, as modified to embody the necessary correction, are as follows.[373]
For the subordinate series of a neutral atom,
“This equation must be used to calculate
whenever the ionization potential of the stage in question is closely followed by the ionization potential of the succeeding stage.”
For the subordinate series of the ionized atom,