Chemistry

Problem

An electron in a hydrogen atom makes a transition from

n = 4

n = 2

, while an electron in a He

^{+}

ion undergoes the same transition (

n = 4 \rightarrow n = 2

). No other effects need be considered. a. (i) Show that the ratio of the photon energies emitted by He

^{+}

and H for these transitions is equal to the square of the ratio of their atomic numbers. b. (ii) Hence obtain the ratio of the wavelengths

\dfrac{\lambda_{\text{He}^{+}}}{\lambda_{\text{H}}}

for the two photons. c. (iii) State, with reason, which of the two photons lies deeper in the ultraviolet region of the electromagnetic spectrum.