Can a hydrogen atom emit characteristic X-ray?

State the characteristic and uses of X-rays

If gamma is the frequency of characteristic X-ray line emitted by a target element of atomic number Z, then Moseley's law is

Solid targets of different elements are bombarded by highly energetic electron beam. The frequcny (f) of the characteristic X -rays emitted from different targets varies with atomic number Z as

STATEMENT-1: In an X-ray tube, the wavelengths of the characteristic X-rays depends on the metal used as target. STATEMENT-2: Metals atomic numbers are best suited for the production of X-rays

What is the originÿof characteristics X-ray? When an electron of a hydrogen atom'jurnps from n = 3 to n = 2 orbit, then what should be the wavelength of the emitted photon? Does it corresponds to visible range? Rydberg const R = 1.1xx10^7 m^-1 .

The ionisation energies of K-shell for cobalt, copper, and molebdenum are 7.8, 9.0 and 20.1 KeV respectively. If any metal out of these is used as target in an X-ray tube operated at 15KV , then (a) the K-series of characteristic X-rays will be emitted only by cobalt (b) the K-series of characteristic X-rays will be emitted only by cobalt & Cu (c) the K-series of characteristic X-rays will be emitted only by cobalt, Cu , Co and Mo (d) the minimum wavelength of continuous X-rays emitted by the three metals will be same