I Emission Spectrum & Energy: Exciting Hydrogen Vapor

pisluca99
Messages
63
Reaction score
4
By exciting hydrogen vapors with heat or electrical discharges, it is possible to obtain the element's emission spectrum. In it, as can be seen, appear multiple wavelengths, each corresponding to a particular orbital electronic transition.
From this it can, therefore, be inferred that heat and electrical discharges do not bring a single fixed energy value to the atom, but bring a range of energy values that allow for the different transitions.
How is this possible? Doesn't an electric discharge have a single definite energy value that corresponds to the ∆V between the electrodes? Likewise, does not a given temperature correspond to only one energy value?
 

Attachments

  • 400px-Hydrogen_transitions.svg.png
    400px-Hydrogen_transitions.svg.png
    9.4 KB · Views: 114
Last edited:
Physics news on Phys.org
The energy supplied to the system excites atoms in a chaotic way to various state of electronic excitation which is an unstable equilibrium. Many different states will be populated but they are constrained to have certain energies by quantum mechanics. These will naturally decay to lower energy emitting light quanta of this characteristic energy.
Of course in a macroscopic population of atoms the excitation and decay are happening concurrently.
 
hutchphd said:
The energy supplied to the system excites atoms in a chaotic way to various state of electronic excitation which is an unstable equilibrium. Many different states will be populated but they are constrained to have certain energies by quantum mechanics. These will naturally decay to lower energy emitting light quanta of this characteristic energy.
Of course in a macroscopic population of atoms the excitation and decay are happening concurrently.
And that is clear. But, for example, considering an electric discharge that excites hydrogen atoms, should it not "possess" a single energy value, corresponding to the ∆V between the electrodes?

For example, there is a ∆V of 200 V between the electrodes, which generates a discharge that has an energy of x kJ (totally invented values for the sake of example only). A precise transition may correspond to this energy value, as well as none, depending on the quantization of the energy levels of the atom.

Instead, exciting hydrogen with this discharge results in the emission of more lambdas, indicating that the electric discharge brings to hydrogen not only the energy value x, but also many others, y, z, m, n, etc., to which the different transitions are associated.
 
No it should not. The discharge is a wildly chaotic event involving turbulent ionized gas. All energies will be availible including some few larger than 200 eV
 
I am not sure if this falls under classical physics or quantum physics or somewhere else (so feel free to put it in the right section), but is there any micro state of the universe one can think of which if evolved under the current laws of nature, inevitably results in outcomes such as a table levitating? That example is just a random one I decided to choose but I'm really asking about any event that would seem like a "miracle" to the ordinary person (i.e. any event that doesn't seem to...
Not an expert in QM. AFAIK, Schrödinger's equation is quite different from the classical wave equation. The former is an equation for the dynamics of the state of a (quantum?) system, the latter is an equation for the dynamics of a (classical) degree of freedom. As a matter of fact, Schrödinger's equation is first order in time derivatives, while the classical wave equation is second order. But, AFAIK, Schrödinger's equation is a wave equation; only its interpretation makes it non-classical...
Back
Top