Electron Energy Level Transitions

[Jimmy87]

When an atom absorbs a photon of light and gets into an excited state, can it ever make a single jump back down to the ground state? For example, if an atom absorbed a blue photon of light then jumped straight back down to the ground state would it then emit a blue photon? How does emission transitions work for humans that continually absorb high energy light photons? For example, if a human is absorbing visible light photons then doesn't the emission photon have to equal that energy gap? So why is the re-radiated photon always infrared for humans? I would guess that the emission is staggered on its way back to the ground state but what dictates this? Any help answering any of these points is much appreciated.

 

[Bill_K]

When an atom absorbs a photon of light and gets into an excited state, can it ever make a single jump back down to the ground state? For example, if an atom absorbed a blue photon of light then jumped straight back down to the ground state would it then emit a blue photon?

Yes, sure.

How does emission transitions work for humans that continually absorb high energy light photons? For example, if a human is absorbing visible light photons then doesn't the emission photon have to equal that energy gap? So why is the re-radiated photon always infrared for humans?

Light doesn't just excite atoms. It interacts with matter in other ways too. When it shines on an object it increases the random thermal motion of the atoms, and the object warms up. Later it gets re-emitted as black body radiation, which for room temperature objects means infrared.

 

[Jimmy87]

Yes, sure.


Light doesn't just excite atoms. It interacts with matter in other ways too. When it shines on an object it increases the random thermal motion of the atoms, and the object warms up. Later it gets re-emitted as black body radiation, which for room temperature objects means infrared.

Thanks for your answer. So what dictates whether you get a discrete electron energy level transitions in some matter or just random thermal motion in other types of matter?

 

[dauto]

You always get both