What kind of light do you expect an electrons jump from 5 to 4 to emit?

When an electron transitions from a higher energy level (n=5) to a lower energy level (n=4), it emits a photon with energy corresponding to the difference between these two levels. This emitted light will be in the infrared region of the electromagnetic spectrum, as the energy difference for such transitions in atoms typically falls within that range. The exact wavelength can be calculated using the Rydberg formula, but it will generally be longer than visible light.