Chemistry Help

An electron in the hydrogen atom is excited from the n = 4 level to the n = 5 level.  What is the energy in Joules corresponding to this energy change?An electron in the hydrogen atom relaxes from n = 5 to n = 2.  What is the frequency (in units of Hz) of the emitted photon?    Note: Your answer must be reported with units of Hz (not s^-1) for this questions.An electron in the hydrogen atom relaxes from n = 5 to n = 4.  What is the wavelength of the emitted photon?  Report your answer in units of m.