Answer:
1.
First of all, let's convert the energy of the absorbed photon into Joules:
The energy of the photon can be rewritten as:
where
h is the Planck constant
c is the speed of light
is the wavelength of the photon
Re-arranging the formula, we can solve to find the wavelength of the absorbed photon:
2. 1.24 eV
In this case, when the electron jumps from the n=4 level to the n=3 level, emits a photon with wavelength
So the energy of the emitted photon is given by the formula used previously:
and using
we find
converting into electronvolts,
Step-by-step explanation: