| Atom | Ionization Potential | Excitation Potential | Max. | Sum | |||
|---|---|---|---|---|---|---|---|
| Mg+ | 14.97 | 8.83 | 9000° | 5.32 | |||
| Ca | 6.09 | 1.88 | 3000 | 3.64 | |||
| Ti | 6.5 | 0.84 | 3500 | 2.7 | |||
| Cr | 6.75 | 0.94 | 3000 | 2.39 | |||
| Mn | 7.41 | 2.16 | 3500 | 3.77 | |||
| Zn | 9.35 | 4.01 | 5600 | 3.0 | |||
| Ca+ | 11.82 | 0.00 | 4000 | 0.00 | |||
| Sr+ | 10.98 | 0.00 | 3500 | 0.00 | |||
| Ba+ | 9.96 | 0.00 | ? | 3000 | 0.00 | ||
| Mg | 7.61 | 2.67 | ? | 4000 | 3.25 |
[[iv]: The Schwarzschild approximation to the boundary temperature is given by the expression
where
is the effective temperature and
the boundary temperature.]
Successive columns give the atom, the critical potentials in volts, the spectral class at which maximum occurs, the assumed
