Chemistry - Atomic Structure Question with Solution | TestHub

Compare photon energies, $13.6(1/n_1^2-1/n_2^2)$ eV.

Lyman 1st line (2 to 1): 10.2 eV.

Paschen 3rd line (6 to 3): $13.6(1/9-1/36)=1.13$ eV.

Pfund 1st line (6 to 5): $13.6(1/25-1/36)=0.166$ eV.

Humphrey 5th line (11 to 6): $13.6(1/36-1/121)=0.266$ eV.

The smallest is the Pfund first line.

Answer: (C).