For a singly-ionized helium atom (He )

PHYSICS · Single correct · A Level · Physics · Particles and radiation · Particles and radiation

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}

(b)

97\,\text{nm}

(c)

26\,\text{nm}

(d)

30\,\text{nm}