Electrons in a hydrogen atom are in a 3p excitation state transitioning     radiative to energy level 2s. Taking into account the spin orbital interaction, determine : i) What is a spin orbit interaction? ii) Show the separation of 3p and 2s energy levels in the energy level diagram without an external magnetic field B iii) Show the separation of 3p and 2s energy levels in the energy level diagram due to the presence of an external magnetic field B iv) State the allowed transition conditions v) Energy emitted when in space without a magnetic field vi) Energy emitted if it is in a space with a magnetic field B = 1T please solve part i

Electrons in a hydrogen atom are in a 3p excitation state transitioning    
radiative to energy level 2s. Taking into account the spin orbital interaction, determine :

i) What is a spin orbit interaction?
ii) Show the separation of 3p and 2s energy levels in the energy level diagram
without an external magnetic field B
iii) Show the separation of 3p and 2s energy levels in the energy level diagram due to the presence of an external magnetic field B
iv) State the allowed transition conditions
v) Energy emitted when in space without a magnetic field
vi) Energy emitted if it is in a space with a magnetic field B = 1T

please solve part i