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Spectral line changes?



 
 
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  #1  
Old August 31st 17, 07:47 AM posted to sci.astro.research
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Default Spectral line changes?

[[Mod. note -- This query started out over in our sister newsgroup
sci.physics.research, but was moved here at my request. This article
should probably have been crossposted between the newsgroups, but I
didn't think of that at the time. Oops...
-- jt]]

Question: Is the spectral line signal for hydrogen different for
hydrogen in hydrogen gas compared with hydrogen in water?

Or, if one were observing the spectral line for some distant
collection of hydrogen gas and then that gas reacted with some
sudden supply of oxygen forming water, would or does the spectral
signal change?

Thanks, in advance.
Ralph Frost
  #2  
Old September 1st 17, 07:05 PM posted to sci.astro.research
Martin Brown[_3_]
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Default Spectral line changes?

On 31/08/2017 07:47, wrote:
[[Mod. note -- This query started out over in our sister newsgroup
sci.physics.research, but was moved here at my request. This article
should probably have been crossposted between the newsgroups, but I
didn't think of that at the time. Oops...
-- jt]]

Question: Is the spectral line signal for hydrogen different for
hydrogen in hydrogen gas compared with hydrogen in water?


I think the answer is yes it will alter the frequencies that the bound
hydrogen atoms emit due to the oxygen distorting the previously perfect
spherically symmetric distribution of the electron wavefunction for an
isolated hydrogen atom. There will also be a bunch of new possible
emission frequencies from a polyatomic molecule too.

The same sort of chemical shift effect is observed in hydrogen bound to
oxygen in water vs hydrogen in fats in NMR which also makes the nucleus
more sensitive to ambient magnetic fields.

http://mriquestions.com/f-w-chemical-shift.html

As a quick hand waving explanation (which might be misleading).


Or, if one were observing the spectral line for some distant
collection of hydrogen gas and then that gas reacted with some
sudden supply of oxygen forming water, would or does the spectral
signal change?


I suspect the hydrogen can only emit the neutral hydrogen line when it
is in the form of isolated neutral atoms of hydrogen. Combine it
chemically with oxygen and it will emit frequencies characteristic of
excited states of OH or H2O as happens in some molecular clouds.

https://www.narrabri.atnf.csiro.au/o.../spectral.html

--
Regards,
Martin Brown
  #3  
Old September 14th 17, 09:24 PM posted to sci.astro.research
Steve Willner
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Default Spectral line changes?

Question: Is the spectral line signal for hydrogen different for
hydrogen in hydrogen gas compared with hydrogen in water?


In article ,
Martin Brown writes:
I think the answer is yes it will alter the frequencies that the bound
hydrogen atoms emit due to the oxygen distorting the previously perfect
spherically symmetric distribution of the electron wavefunction for an
isolated hydrogen atom. There will also be a bunch of new possible
emission frequencies from a polyatomic molecule too.


That last is hugely important. Water has a vast number of spectral
lines because of the multiple ways the molecule can vibrate and
rotate. These lines are mostly at infrared through millimeter
wavelengths. If the pressure or water abundance is high, there are
so many lines that they blend together in bands. Even at low
pressure and abundance, observations with low spectral resolution
will see bands, not lines.

I suspect the hydrogen can only emit the neutral hydrogen line when it
is in the form of isolated neutral atoms of hydrogen.


If this means the hyperfine structure line at 21 cm, I don't think
water has any such line because there are an even number of
electrons. A water ion with an odd number of electrons would have a
line coming from the same physics, but the energy level separation
and hence the line frequency would surely shift.

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Steve Willner Phone 617-495-7123
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  #4  
Old September 30th 17, 08:32 PM posted to sci.astro.research
John Heath
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Posts: 13
Default Spectral line changes?

[Moderator's note: Quoted text snipped. -P.H.]

I was having fun trying to come up with a spectrum analyzer that would
make a distinction between copper iron and gold. Clearly the motive was
financial gains rather than than science. In doing this research it
became apparent that the high Q spectrum lines of a gas were very
different from solids. The meaning of Q is the degree of well defined
spikes in the spectrum VS low Q soft spectrum that changes at a
disappointing slow rate. For example the difference between copper and
gold from red to blue is just a fluffy soft cure without any sharp
identifying spikes to say you hit pay dirt. A gas on the other hand such
as O H or N has high Q spikes in the infrared part of the spectrum
making identification easy. In short a gas liquid and solid are very
different when it comes to their absorption and reflective spectrum.

  #5  
Old October 2nd 17, 09:24 PM posted to sci.astro.research
Martin Brown[_3_]
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Posts: 189
Default Spectral line changes?

On 30/09/2017 20:32, John Heath wrote:
[Moderator's note: Quoted text snipped. -P.H.]

I was having fun trying to come up with a spectrum analyzer that would
make a distinction between copper iron and gold. Clearly the motive was
financial gains rather than than science. In doing this research it
became apparent that the high Q spectrum lines of a gas were very
different from solids. The meaning of Q is the degree of well defined
spikes in the spectrum VS low Q soft spectrum that changes at a
disappointing slow rate. For example the difference between copper and
gold from red to blue is just a fluffy soft cure without any sharp
identifying spikes to say you hit pay dirt. A gas on the other hand such
as O H or N has high Q spikes in the infrared part of the spectrum
making identification easy. In short a gas liquid and solid are very
different when it comes to their absorption and reflective spectrum.


You don't do it at optical wavelengths...

There is a simple way to do metals with X-ray Fluorescence spectroscopy
which would work fairly well - Bruker hold some key XRF patents:

http://alloytester.com/xrf-technology

And it is handheld portable (other brands are available).

One of the applications is gold purity. The other way to do it would by
laser ablation mass spectrometry but they are not so portable.

--
Regards,
Martin Brown
  #6  
Old October 5th 17, 04:31 PM posted to sci.astro.research
John Heath
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Posts: 13
Default Spectral line changes?

On Monday, October 2, 2017 at 4:24:54 PM UTC-4, Martin Brown wrote:
On 30/09/2017 20:32, John Heath wrote:
[Moderator's note: Quoted text snipped. -P.H.]

I was having fun trying to come up with a spectrum analyzer that would
make a distinction between copper iron and gold. Clearly the motive was
financial gains rather than than science. In doing this research it
became apparent that the high Q spectrum lines of a gas were very
different from solids. The meaning of Q is the degree of well defined
spikes in the spectrum VS low Q soft spectrum that changes at a
disappointing slow rate. For example the difference between copper and
gold from red to blue is just a fluffy soft cure without any sharp
identifying spikes to say you hit pay dirt. A gas on the other hand such
as O H or N has high Q spikes in the infrared part of the spectrum
making identification easy. In short a gas liquid and solid are very
different when it comes to their absorption and reflective spectrum.


You don't do it at optical wavelengths...

There is a simple way to do metals with X-ray Fluorescence spectroscopy
which would work fairly well - Bruker hold some key XRF patents:

http://alloytester.com/xrf-technology

And it is handheld portable (other brands are available).

One of the applications is gold purity. The other way to do it would by
laser ablation mass spectrometry but they are not so portable.

--
Regards,
Martin Brown


I can see from googling gold has a 9.5 K volt peek followed by an 11 K
volt peek

Problem is you have to be up close with a x-ray source to ping the inner
electrons. I wonder if a good lightning strike would be enough for
detecting at a distance , Hmmm.

 




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