Physics

Problem

For a singly-ionized helium atom (He

^{+}

), the energy of a bound state is given by

E_n=-54.4\,\text{eV}/n^{2}

. An electron in this ion makes a single transition directly from

n=3

n=1

. Which of the following is closest to the wavelength of the emitted photon? a)

34\,\text{nm}

97\,\text{nm}

26\,\text{nm}

30\,\text{nm}