frequency of an atom

[gib65]

Take a hydrogen atom into consideration. We can say that its frequency is how many times per second (or nanosecond?) its electron orbits the nucleus. This makes sense according to the Rutherford model, but what about in the case of the standard model. As I understanding it, the standard model has electrons surrounding the nucleus as "electron clouds" - that is, they don't literally orbit the nucleus. Therefore, is it still correct to say that the atom has a frequency? Is the electron still undergoing so many ___s per second? And what are those ___s?

[swansont]

The context of frequency is in transitions; if you put an atom in a superposition of 2 states, you can say it's oscillating at the frequency difference between those states.

 

The Bohr model has electrons as standing waves. Even in that flawed picture, one wouldn't necessarily talk about an orbital frequency.

[gib65]

The context of frequency is in transitions; if you put an atom in a superposition of 2 states, you can say it's oscillating at the frequency difference between those states.

 

The Bohr model has electrons as standing waves. Even in that flawed picture, one wouldn't necessarily talk about an orbital frequency.

 

OK, so let's say the frequencies of the two states were 10 MHz and 13 MHz (I have no idea if this is to scale ), then the atom could be said to be oscillating at 3 MHz?

[swansont]

There's no basis to say a state was at 10 MHz or 13 MHz. You can measure that it takes a 3 MHz photon to induce a transition, and that tells you the separation between the states.

[BenTheMan]

if you put an atom in a superposition of 2 states, you can say it's oscillating at the frequency difference between those states.

 

I agree, I think. As long as the oscillation time is on order of hbar times a few, right?

 

(So, VERY quickly.)

[swansont]

I agree, I think. As long as the oscillation time is on order of hbar times a few, right?

 

(So, VERY quickly.)

 

Vey quickly, yes (typically). It's the basis for how atomic clocks work: you let the atoms oscillate between the two states after you've put them in the superposition.

[Riogho]

Uh... let me a find a picture.

 

You need to forget the Bohr Model of the atom, it is inaccurate.

 

Electron orbitals do not orbit in circles. They look like that.

 

First fillign up the 1s level, then the 2s2p then the 3s3p3d

etc etc

 

It's called electron configuration, look it up on wiki.

[gordman]

I still have a lot to learn from you guys, you are brilliant.

[doG]

Here's a related story on Molecular Chords you might enjoy....

[granpa]

the electron cloud can occillate around the nucleus. in fact, if the charge density is uniform, then it will resonate.