How do electrons change states on their own?

[ephen wilb]

What are the number of states available to the electrons, and what is the difference between the ease of getting electrons to change states considered against the ease with which they change states by themselves? Can you give an example where they change states by themselves?

 

[bhobba]

What are the number of states available to the electrons,

As elements of a Hilbert space its infinite

and what is the difference between the ease of getting electrons to change states considered against the ease with which they change states by themselves?

Well they can spontaneously changes state - so that's obiously the easiest since it requires nothing.

Can you give an example where they change states by themselves?

Yes - spontaneous emission
http://en.wikipedia.org/wiki/Spontaneous_emission

The cause is fluctuations of the vacuum. Note such fluctuations are not real - they are simply mathematical artefacts of the perturbation methods used.

Thanks
Bill