A Doubly-Ionized Lithium Atom $\mathrm { Li } ^ { + + }$

Multiple Choice

A doubly-ionized lithium atom $\mathrm { Li } ^ { + + }$ , which has 3 protons, undergoes a transition from the $n = 5$ state to the $n = 4$ state. What is the wavelength of the photon which is emitted during this
transition? $\left( c = 3.00 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } , h = 6.626 \times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s } , 1 \mathrm { eV } = 1.60 \times 10 ^ { - 19 } \mathrm {~J} \right)$

A) $650 \mathrm {~nm}$
B) $350 \mathrm {~nm}$
C) $550 \mathrm {~nm}$
D) $750 \mathrm {~nm}$
E) $450 \mathrm {~nm}$