Shifting atomic spectrum

[Relena]

Can the absorption spectrum of an atom be shifted significantly using electric or magnetic fields ?
such that to turn red to blue or something ?

Another question, can atoms be excited to a certain energy level by applying external fields only with calculated energy ?

thanks

 

[alxm]

Can the absorption spectrum of an atom be shifted significantly using electric or magnetic fields ? such that to turn red to blue or something ?

It can be shifted (See Zeeman, Stark effects). But not enough to change the color of an object, in practice. This would require too strong a field.

Another question, can atoms be excited to a certain energy level by applying external fields only with calculated energy ?

Does a photon count as a field?
Anyway, yes static magnetic or electric field could excite an electron as well, but would require a field much much stronger than anything we have. Consider that some of the strongest fields around are in NMR and MRI machines, and these have no effect on chemistry at all. (which would've been the case if they were causing any excitations.