What happens when an element is heated?

[MaterSammichM]

Let's say we have a bar of 100% pure iron.
We know that on a 'human' level- that which we can see with the naked eye, Iron (Fe) will "grow" when heated.
But on an atomic level,
Is this due to exansion of the atomic particles,
or due to a growth of the atom itself,
or due to an expansion in the area between the valence shells of the atoms?

Thanks

 

[russ_watters]

The effect is entirely due to the separation between the atoms increasing.

 

[phinds]

It is not expansion/growth, it's the energy level of the atoms. They get so excited that they give off photons, much the same way I do when I see a really pretty girl.

 

[MaterSammichM]

Thank you Russ.
Phinds, perhaps you were joking, but yeah, the size of the metal does expand, just like it contracts when cooled sufficiently. As for your other statement, I think pharmaceuticals are available to help.

 

[phinds]

Thank you Russ.
Phinds, perhaps you were joking, but yeah, the size of the metal does expand, just like it contracts when cooled sufficiently. As for your other statement, I think pharmaceuticals are available to help.

Sorry, yeah, I was joking. I mean we both give off photons when heated but I didn't know about the expansion. Fortunately we have russ and others here to correct my boneheaded statements. Actually, the kind of pharmaceuticals I prefer just make it worse.

EDIT: I want you to notice that I managed to avoid any jokes about my own expansion under the conditions mentioned.

 

[MaterSammichM]

No problem. One thing though, I don't think that the metal would have to be heated to the point of producing photons (ie Red Hot) in order for thermal expansion to occur.

 

[phinds]

No problem. One thing though, I don't think that the metal would have to be heated to the point of producing photons (ie Red Hot) in order for thermal expansion to occur.

It doesn't have to be red hot to emit photons, it will do that anyway. If it is hotter than its surroundings, it will emit more than it receives and if it is cooler than its surroundings it will emit fewer than it receives, but it will emit them in any case (well, maybe not in the case of supercooling it to near zero absolute).

 

[MaterSammichM]

Much appreciated Phind