Question

calculate the wavelength of the first line in the lymen series of hydrogen spectrum​

Answer 1

since the electron is de-exited from 1(st) exited state (i.e n=2) to ground state (i.e n=1) for first line of Lyman series. Since the atomic number of Hydrogen is 1. λ = 4/3⋅912 A. 1/R = 912 A