What should the  energy of an incident photon be in electron volts to excite a hydrogen atom from its ground state to its n = 5 state?

The electron of a hydrogen atom requires 1.633*10-18 J to be excited from n = 1 Bohr energy level to the n = 2 level.  This energy can be obtained from the absorption of a photon.  What would be the wavelength of this photon?

What wavelength of light is emitted by a hydrogen atom in which an electron makes a transition from the n = 7 to the n = 4 state? Enter this wavelength expressed in nanometers.  1nm = 1 x 10-9m.  Assume the Bohr model.

(a) If an electron makes a transition from the n = 6 Bohr orbit to the n = 2 orbit, determine the wavelength of the photon created in the process. 416 nm (b) Assuming that the atom was initially at rest, determine the recoil speed of the hydrogen atom when this photon is emitted.