Answer:
c. There would be a series of spectral lines in hydrogen with the longest wavelength one at 122 nm.
d. The hydrogen atom binds its electron more tightly than the sodium atom does, and would require more energy to remove its electron completely.
Step-by-step explanation:
The hydrogen atom which changes from the excited state to the lower ground state, it emits light having a wavelength of 122 m. And the sodium atom also gets excited and emits light at 589 nm when it moves from the 1st excited state to the lowest excited state.
Therefore, when the electrons jumps from the 1st excited state to the ground state, only one wavelength is observed as there is only one transition.
The hydrogen atom will bind the electron tightly but the sodium atom does not and would require more energy to remove the electron the electron completely as the binding energy is higher when the electron is closer to the nucleus.