Answer to Question #21138 in Physical Chemistry for habib

Question

how can negative ions exist in gasses?

Answer 1

Nearly 90% of atoms are able to form stable negative ions in the gas phase by attaching an electron to the ground state electron configuration, the short-range potential can usually only bind the fine- or hyperfine-structure states of the ground state term or in case of several terms of the energetic lowest lying one, while the Coulomb potential supports an infinite number of bound states, converting into Rydberg series at the ionization threshold.