How is light reflected off a particular material?

[mahela007]

How is light reflected off a particular material at atomic level? And how does that relate to blackbody radiation?

[swansont]

Absorption and re-emission of the photon.

 

Blackbody radiation is from the acceleration of charges during collisions or from vibrations.

[mahela007]

what do you mean by "acceleration of charges during collisions"?

[Klaynos]

what do you mean by "acceleration of charges during collisions"?

 

During a collision there is an acceleration, the acceleration of any charged particle results in that particle radiating (emitting photons). This emission is called blackbody emission.

[mahela007]

but what are the two particles which are colliding? is it two adjacent nuclei?

[swansont]

Often it is the quasi-free electrons in the conduction band of a conductor.

[mahela007]

I think understanding what "quasi free" electrons are is quite beyond me.. ;-)

So.. basically it's not electron jumping up and down in the energy levels that causes black body radiation but the vibrational energy of atoms right?

[swansont]

I think understanding what "quasi free" electrons are is quite beyond me.. ;-)

So.. basically it's not electron jumping up and down in the energy levels that causes black body radiation but the vibrational energy of atoms right?

 

At thermal energies (i.e. room temperature) electrons in the conduction band are bound to the material, but within that band are free to move around fairly easily and collide. They tend to stay within the band. (hence the "quasi")

 

It's not from jumps between levels, which would give you a discrete spectrum.

[Bishadi]

I think understanding what "quasi free" electrons are is quite beyond me.. ;-)

So.. basically it's not electron jumping up and down in the energy levels that causes black body radiation but the vibrational energy of atoms right?

 

that resonant energy is em (hence the photon)

 

eg... note what the mass is (elemental structure), the volume and the environment. Each will have different thresholds just like each emit different wavelengths (photons) and noted quite easily with the colors we see.

 

a method to see all that mentioned above is to heat up a piece of iron to various temperatures.