The figure below shows some energy levels of the lithium atom. I) Considering the conditions for atomic transitions, what should be the shortest wavelength in the lithium state emission spectrum starting from the 4s excited state? Justify the calculations. II) What must be the longest wavelength that must be absorbed by the atom in the ground state so that the emission at 816 nm is possible to be observed? Justify your answer. III) What must be the slowest speed of an electron such that, after colliding with the atom in the ground state, the wavelength 816 nm can be observed in the emission spectrum? Justify the calculations.

The figure below shows some energy levels of the lithium atom. I) Considering the conditions for atomic transitions, what should be the shortest wavelength in the lithium state emission spectrum starting from the 4s excited state? Justify the calculations. II) What must be the longest wavelength that must be absorbed by the atom in the ground state so that the emission at 816 nm is possible to be observed? Justify your answer. III) What must be the slowest speed of an electron such that, after colliding with the atom in the ground state, the wavelength 816 nm can be observed in the emission spectrum? Justify the calculations.