4p-5s Transitions in Y VII, VIII, Zr VIII, IX, Nb IX, X and Mo X, XI

The spectra of Y VII, VIII, Zr VIII, IX, Nb X and Mo X, XI are studied for the first time and our 1971 analysis of Nb IX is improved. By analyses of the transitions 4s 24pk -4s 24p k-15s all the levels of the configurations 4p 3, 4p 25s, 4p 2 and 4p5s are established in the spectra concerned.