WHY can't electrons absorb photons of any energy?

[CAH]

hey!

So oribital electrons can only absorb photons if they are the exact amount of energy between energy levels unless it is more than the ionisation energy.

But why can't they? Couldn't they just emit the extra energy or 'keep' it?

Thanks

 

[mfb]

Couldn't they just emit the extra energy

That process is possible, but very unlikely. Raman spectroscopy uses it, for example.

or 'keep' it?

They cannot. They cannot have an energy which does not correspond to one of the energy levels.