Why High Energy Lines in Balmer Series Not Visible?

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Homework Help Overview

The discussion revolves around the visibility of high energy lines in the Balmer series of hydrogen's emission spectrum. Participants explore why these lines are not observable with a spectroscope, particularly focusing on the nature of emitted radiation and its relation to the visible spectrum.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • The original poster questions whether the invisibility of high energy lines is due to their placement outside the visible spectrum and their lower intensity compared to lower energy lines. Some participants provide insights into the relationship between energy levels and emitted wavelengths, while others discuss the role of temperature and the Boltzmann distribution in determining the probability of electrons occupying higher energy states.

Discussion Status

The discussion is active, with participants sharing various perspectives on the reasons behind the invisibility of high energy lines. Some have provided clarifications regarding the wavelengths associated with different energy levels, while others have raised questions about the influence of temperature on electron states. There is no explicit consensus yet, but multiple interpretations are being explored.

Contextual Notes

Participants reference specific wavelengths and their corresponding energy levels, noting that emissions from energy levels greater than n=6 fall into the ultraviolet spectrum, which is not visible. The discussion also touches on the implications of temperature on the likelihood of electrons reaching higher energy states.

jubba
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in the balmer series the the higher energy level lines from the spectra are not observable using a spectroscope.

is this because:
they are outside the visible spectrum
and
the intensity of the lines at high energy levels are much lower than the lower energy lines?

If any of my reasons are wrong please correct me and if i have missed out something please tell me.
:rolleyes:
 
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The little chart that I have shows that for terms greater than n = 6
(to n = 2, the Balmer series), the emitted radiation would fall in the ultraviolet spectrum. At n = 7 the wavelength emitted is 3970 Angstroms
and becomes progressivlely shorter for the higher terms. Hope this
answers your question.
 
jubba said:
...of the lines at high energy levels are much lower than the lower energy lines?...
:rolleyes:

I am not sure but I think that the probability of electron being in certain energy state depends on the temperature following the Boltzmann distribution. So if the electrons aren't in a higher energy state then they can't relax and emit the radiation.
 
NotMrX said:
I am not sure but I think that the probability of electron being in certain energy state depends on the temperature following the Boltzmann distribution. So if the electrons aren't in a higher energy state then they can't relax and emit the radiation.
Correct. The intensity which is a measure of the number of photons is related to the number of atoms which achieve a particular energy state. The highert the temperature, the more likely an atom will achieve a higher energy level through collisions. The 'color' of stars is related to temperature of the photosphere.

Balmer Series (Second) (visible light) n=2 limit = 365 nm

n=3, λ = 656 nm α, color emitted: red
n=4, λ = 486 nm β, color emitted: bluegreen
n=5, λ = 434 nm γ, color emitted: violet
n=6, λ = 410 nm δ, color emitted: violet

The remaining are UV, which would not be visible.

Lyman lines are UV and Paschen are infrared.
http://en.wikipedia.org/wiki/Balmer_series
 

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