Hydrogen atoms in the ground state are excited by monochromatic radiation of wavelength 975 Å. Find the number of spectral lines in the resulting emission spectrum.
Physics · Atomic Structure and X-rays
JEE Mains Practice

Question

Hydrogen atoms in the ground state are excited by monochromatic radiation of wavelength 975 Å. Find the number of spectral lines in the resulting emission spectrum.

G1 Physics · Accepted Answer

975 Å corresponds to 12.72 eV, exciting hydrogen from n=1 to n=4. The number of possible emission lines is n(n−1)/2=4×3/2=6.