the necessary centripetal force for the electron to revolve is beibg provided in the form of the electrostatic force of attraction between the electron and the protons in the nucleus.

u need to multipy the charge on the proton with the atomic no." Z" to get the charge on the nucleus during solving the numericals.

v =( Z e²/4IIE₀ m r)^1/2

plz rate if use ful and correct me if im wrong