Problem: Though the energy eigenstates of an electron in an atom are infinitely long-lived, perturbations (such as two atoms colliding, for example) can cause transitions between states. When that occurs the energy difference is associated
with the emission or absorption of a photon with the required energy.

Part A: Assuming the model of an atom described in part 1 is valid, what is the wavelength (in nm) of a photon needed to excite an electron from the ground state to the first excited state?

Please explain how you came to your conclusion.