Answer:
11971nm
Explanation:
The energy in an atom is given by: [tex]E_{n} =13.6 eV/n^{2}[/tex]
To n= 4; [tex]E_{4}=13.6 eV/16[/tex]
To n= 8; [tex]E_{8}=13.6 eV/64[/tex]
Calculate the diference in the energy levels to know the energy of the absorbed photon.
[tex]E_{4-8}=0.63 eV[/tex]
To calculate the wavelength of the photon, substitute the values in the next equation:
[tex]\lambda=hc/E[/tex]
Where h is the Plank's constant with a known value (4.14*10^-15 eV), c is the ligth velocity (3*10^8 m/s) and E is the energy of the photon (0.63 eV).
[tex]\lambda=1971 nm[/tex]
