B How does the hydrogen line spectrum work with only one orbit?

[Mr X]

Since hydrogen atom has only one orbit, how does the hydrogen line spectrum work? I saw somewhere, that infinite orbits(n) are possible, but wouldn't having too much energy end up causing the electron to break free from the nucleus and thus ending up as a free electron?
So when exactly does those photons get released when there is only one energy level existing?

 

[berkeman]

Welcome to PF.

Since hydrogen atom has only one orbit

I think you mean "orbital"?

https://en.wikipedia.org/wiki/Atomic_orbital

I saw somewhere, that infinite orbits(n) are possible

Please try to find where you saw that and post a link to it. That will help us explain the subject better for you. Thanks.

https://en.wikipedia.org/wiki/Hydrogen_atom

 

[Borek]

In general there is no "orbit" as such - it is just a simplified explanation of what is happening, one used in so called "planetary model", that was used to explain observed properties of a hydrogen atoms before the quantum physics was born. There are orbitals. They are not circular like an orbit, it is a bit more complicated.

But let's keep to this "orbit" thing, as it should be enough here. Yes, there are infinitely many "orbits" that electron can be on - but they get closer to each other for higher energies (something like 1-\frac 1 {n^2} - it can have infinitely many values for n being a natural number, but none of these is larger than 1). Electron can occupy one "orbit" at any given moment, but it can jump between them - either emitting or absorbing energy. If it happens that the electron absorbs more energy than the limit (which we call ionization energy) it jumps "over" the highest energy orbit and leaves the atom.

 

[Baluncore]

Since hydrogen atom has only one orbit, how does the hydrogen line spectrum work?

Only the lowest orbital is normally occupied, but there are other usually unoccupied orbitals above that with higher energy levels.

 

[Drakkith]

So when exactly does those photons get released when there is only one energy level existing?

There isn't a single energy level that exists, there are an infinite number. It's just that a non-ionized hydrogen atom has a single electron and thus can only populate one of its energy levels at a time. The different emission/absorption lines come from electrons moving between all of these different energy levels one at a time. But there's more than one hydrogen atom in a gas cloud so you can see multiple lines at the same time since different atoms get excited to different energy states.

 

[Mr X]

In general there is no "orbit" as such - it is just a simplified explanation of what is happening, one used in so called "planetary model", that was used to explain observed properties of a hydrogen atoms before the quantum physics was born. There are orbitals. They are not circular like an orbit, it is a bit more complicated.

But let's keep to this "orbit" thing, as it should be enough here. Yes, there are infinitely many "orbits" that electron can be on - but they get closer to each other for higher energies (something like 1-\frac 1 {n^2} - it can have infinitely many values for n being a natural number, but none of these is larger than 1. Electron can occupy one "orbit" at any given moment, but it can jump between them - either emitting or absorbing energy. If it happens that the electron absorbs more energy than the limit (which we call ionization energy) it jumps "over" the highest energy orbit and leaves the atom.

something like 1−1n2 - it can have infinitely many values for n being a natural number, but none of these is larger than 1)

So the orbitals become closer to each other as the principle quantum number increases. What does (1-1/n²) represent exactly? And what's the importance of 1 here?

 

[DrClaude]

So the orbitals become closer to each other as the principle quantum number increases. What does (1-1/n²) represent exactly? And what's the importance of 1 here?

https://en.wikipedia.org/wiki/Rydberg_formula#For_hydrogen
http://hyperphysics.phy-astr.gsu.edu/hbase/hyde.html

 

[Mr X]

Electron can occupy one "orbit" at any given moment, but it can jump between them - either emitting or absorbing energy. If it happens that the electron absorbs more energy than the limit (which we call ionization energy) it jumps "over" the highest energy orbit and leaves the atom

Yeah. What I'm asking is, isn't the limit of the hydrogen nucleus 1s orbital? And since spin number does not affect energy, then there should be only only one possible energy level of electron that's connected to the nucleus of a hydrogen atom, So to where does the electron jump to, in order to produce emmision absorption spectrum?

Sorry if there's anything wrong with my phrasing. I am still getting used to it

 

[Mr X]

https://en.wikipedia.org/wiki/Rydberg_formula#For_hydrogen
http://hyperphysics.phy-astr.gsu.edu/hbase/hyde.html

This was a bit beyond my level, but I got the gist of it. So even the quantum field fluctuations and electron spin affects the spectrum.

But what does the fractions after 2p and so, represents? Are those the spins(spin quantum number) of electrons?

 

[Borek]

Yeah. What I'm asking is, isn't the limit of the hydrogen nucleus 1s orbital?

No, it is not the limit. 1s is where the electron sits if not excited, but when excited it can jump to any other orbital. It is just that in the hydrogen atom always only one orbital is occupied (and actually only in half).

And since spin number does not affect energy,

Not exactly, what you asked about in your second post (about these fractions) is where the spin comes into the picture - it is what is called a "hyper-fine structure". Follow the link on the hyperphysics site for more details (basically there is a tiny interaction between nucleus spin and electron spin).

then there should be only only one possible energy level of electron that's connected to the nucleus of a hydrogen atom,

No - again, think about an electron on an orbital as it was an electron on the "orbit" - while there is only one orbital/orbit occupied at any given time, there are infinitely many possible and electron still can jump between them (emitting or absorbing energy).

 

[Mr X]

No, it is not the limit. 1s is where the electron sits if not excited, but when excited it can jump to any other orbital. It is just that in the hydrogen atom always only one orbital is occupied (and actually only in half).
Not exactly, what you asked about in your second post (about these fractions) is where the spin comes into the picture - it is what is called a "hyper-fine structure". Follow the link on the hyperphysics site for more details (basically there is a tiny interaction between nucleus spin and electron spin).
No - again, think about an electron on an orbital as it was an electron on the "orbit" - while there is only one orbital/orbit occupied at any given time, there are infinitely many possible and electron still can jump between them (emitting or absorbing energy).

I got it. Thank you for the help.