Frequency of characteristic X-rays for elements and Frequencies of transitions between corresponding states?

Question

True or False....Frequencies of transitions between corresponding stationary states in hydrogen, deuterium, and tritium are identical.

And

Frequency of characteristic X-rays for elements depend on: (Atomic weight or Atomic Number?)

Any help is appreciated.

Answer 1

1 Very small, hyperfine, corrections due to nuclear mass will occur especially in external electric or magnetic fields.

2 Lines depend on type of material so Atomic Number is important - but again small variations will occur because of Z.