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Vibrational Frequency CO2 Global Warming


BanterinBoson

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6 hours ago, BanterinBoson said:

 

23 hours ago, swansont said:

It gets complicated. You'd have to integrate the earth's emission over the absorption band of the CO2, the look at the CO2 emission profile (probably a dipole radiation pattern, so it's not isotropic, but that might not matter). And that's just one absorption. You would have to look at whether re-radiated is then absorbed, and then a third absorption, etc. for the entire thickness of the atmosphere.

Fortunately, people have done this already. Probably no need to re-invent the wheel. Just find what they've done.

I'd be content just knowing how to figure it for one abstract molecule without the complications of the entire atmosphere.  Reinventing wheels teaches me how to make wheels ;)

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edit: such as http://clivebest.com/blog/?p=4265

models calculating this (i.e. search terms to use) will include Beer's law and Kirchoff's law

That's a helpful link and I will have to study that more.  The last comment on the page tipped me off to Stefan-Boltzmann which allows me to describe power in terms of area of a blackbody, which is what co2 is at a certain frequency.  At least I can say "this many watts goes to space and that many heads to earth", but first I have to decide how much area a co2 molecule has and what T will be.

The Beer's law requires an optical depth, so I'm not sure that applies here.

I'm still struggling to learn the nomenclature:

Roughly, the temperature of a body at rest is a measure of the mean of the energy of the translational, vibrational and rotational motions of matter's particle constituents, such as molecules, atoms, and subatomic particles. The full variety of these kinetic motions, along with potential energies of particles, and also occasionally certain other types of particle energy in equilibrium with these, make up the total internal energy of a substance. Internal energy is loosely called the heat energy or thermal energy in conditions when no work is done upon the substance by its surroundings, or by the substance upon the surroundings.  https://en.wikipedia.org/wiki/Thermodynamic_temperature

That looseness is what makes this difficult and the last thing I want to start doing is associating heat with stored energy.  Maybe the best way to attack this is to make a spreadsheet of every term (heat, internal energy, thermal energy, radiance, spectral radiance, radiant flux, temperature, thermodynamic temperature, yada yada) so I can have it all in front of me to make sense of.

The math and the concepts are straightforward, so the language is the only barrier.

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Light is heat when it comes from thermal radiation. Light from non-thermal sources e.g. a laser, or fluorescent light, is not heat. (it would be included in "work" in the energy equation)

Huh?  Why do you want to confuse me like that? lol!  How is light from a laser not heat?  How is a fluorescent light doing work?

I'm getting a variety of answers:

1) In thermodynamics, heat is often contrasted with work: heat applies to individual particles (such as atoms or molecules), work applies to objects (or a system as a whole). Heat involves stochastic (or random) motion equally distributed among all degrees of freedom, while work is directional, confined to one or more specific degrees of freedom.  https://en.wikipedia.org/wiki/Heat

2) Work is any energy transfer that does not carry entropy. Heat, on the other hand, is any energy transfer that carries entropy.  

3) Work is the mechanical transfer of energy to a system or from a system by an external force on it.  Heat is the non-mechanical transfer of energy from the environment to the system or from the system to the environment because of a temperature difference between the two.  The conversion of mechanical energy (work) to heat is very efficient, nearly 100%. But the conversion of thermal energy (heat) to work is not so because heat is a low grade energy.  https://www.quora.com/In-thermodynamics-what-is-the-difference-between-work-and-heat-I-was-thinking-about-this-when-studying-Carnot-Cycles-and-adiabatic-processes-How-can-a-system-do-work-in-isolation-What-is-it-doing-work-on-Where-is-that-energy-going

I like this one:

4) You are right. Microscopically, work and heat are just about the same. Both involve molecular collisions transfer energy from one object to the other.

Work involves a kind of "coherent" transfer in a manner of speaking, in which the collisions are predominantly, and to an extreme degree, in one direction. Also, typically the force is applied to one location on the object. And importantly, the boundary of the system is displaced. (E.g. translation or deformation)

On the other hand, transfer of energy by heat is "incoherent", many directions, and typically in all directions. And importantly, the boundary of the system is not displaced.

Finally, everyday phenomena fall into one or the other category, and they differ in their macroscopic behavior. Loosely speaking, when heat is transfered the temperature rises. When work is done, the boundary of the system changes. Of course adding heat generally also results in the boundary moving [say, expanding], and work generally results in a temperature change [Joule's experiment]. I'm trying to motivate the macroscopic separation between work and heat without a lengthy discussion.

To the engineers who first worked all of this out, the very existence of atoms was unknown. To them, the separation between heat and work was very clear. They had little reason to view them as manifestations of the same microscopic process. They thought that heat was a physical fluid. In any event, their remarkable achievements have stood the test of time.  https://physics.stackexchange.com/questions/135539/why-work-w-and-heat-q-are-different-concepts

What do you think?  What's the best way to write distinct definitions for work and heat?

 

18 hours ago, swansont said:

You can excite an atom in other ways (e.g. collisions with other atoms). The energy levels exist independent of photons. Therefore it would be wrong to say that the energy level depends on the photon.

Regardless how we excite the atom (photon or collision) it is still resonance that determines the energy level of the electron, right?  So it's the mass and bond strengths that determine the energy levels.  I don't understand why that would not be correct.

Here is what I said before:

It seems like it would be the resonance of the atom that determines the point where a photon would be absorbed and that would define the difference in energy levels.  Not the other way around, which is the difference in energy levels determines if a photon is absorbed and that defines the resonance because it doesn't make sense that way.  It's putting the cart before the horse.

18 hours ago, swansont said:

Again, atomic structure can be calculated and/or investigated, and it exists, independent of the proximity of any photons. 

Right, as a function of mass and bond strengths which determine both resonance and energy levels.

 

 

20 hours ago, studiot said:

Yes I noticed so hopefully you understand the significance of the separation of charge

But sadly I can only conclude the following from this address as the only response to an explanation, already twice given:-

Well, I wasn't done replying to your post as I wasn't done studying it in hopes of replying with something that would be to your satisfaction.

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I take this last bit to mean

"My mind is made up so don't confuse me with the facts"

Not at all and I have no idea how you came to that conclusion as I took special care to prevent anyone from coming to that conclusion.  Anyway, I've discovered the limits to my patience for walking on eggshells only to still be incapable of making you happy, so whatever.  I'll figure it out with or without your help and if having your help means the continual negotiation of derogatory implication then I'd prefer to go-it alone.  Thanks for trying.

16 hours ago, John Cuthber said:

First, you stop trying to run before you can walk.

Then you take classes in physics, maths and quantum mechanics.

Then, with luck you can apply time dependent perturbation theory to the question.

Alternatively, you can read it off the graph posted in the OP

 

I really don't know why I am bothering but I will spell it out in simple sentences.

 

  1. You have asked a Chemistry question in the Chemistry section of this forum.
  2. You insist in the above quoted definition of Resonance.
  3. I have not told you this is incorrect.
  4. I have told you that your definition is appropriate to the Physics of Mechanical vibrating systems.
  5. I have also told you that there is a separate, very different  definition in Chemistry.
  6. I have also told you that this usage has nothing to do with vibrating systems. In fact it applies to the carbon dioxide molecule whether it is vibrating or not.
  7. You have steadfastly refused to discuss this.

In these circustances I can only suggest adding Chemistry to John Cuthber's list for you to study.

 

I have also told you that the vibrations in question are not due to the promotion of electrons to higher energy levels.
Again in your responses you steadfastly continue to promote this fiction, as with the quoted response to swansont.

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7 hours ago, BanterinBoson said:

I'd be content just knowing how to figure it for one abstract molecule without the complications of the entire atmosphere.  Reinventing wheels teaches me how to make wheels ;)

If it's just a single molecule, it's just absorption and re-radiation, as has been explained.

7 hours ago, BanterinBoson said:

That's a helpful link and I will have to study that more.  The last comment on the page tipped me off to Stefan-Boltzmann which allows me to describe power in terms of area of a blackbody, which is what co2 is at a certain frequency.  At least I can say "this many watts goes to space and that many heads to earth", but first I have to decide how much area a co2 molecule has and what T will be.

The Beer's law requires an optical depth, so I'm not sure that applies here.

It applies to the whole system, which is what needs to be solved for the topic of global warming. The atmosphere has an optical depth.

7 hours ago, BanterinBoson said:

 Huh?  Why do you want to confuse me like that? lol!  How is light from a laser not heat?  How is a fluorescent light doing work?

Because of how heat is defined.

7 hours ago, BanterinBoson said:

I'm getting a variety of answers:

Which are consistent with each other.

7 hours ago, BanterinBoson said:

  Heat is the non-mechanical transfer of energy from the environment to the system or from the system to the environment because of a temperature difference between the two.  

Lasers do not rely on a temperature difference. Therefore, they cannot be heat.

7 hours ago, BanterinBoson said:

Regardless how we excite the atom (photon or collision) it is still resonance that determines the energy level of the electron, right?  So it's the mass and bond strengths that determine the energy levels.  I don't understand why that would not be correct.

Here is what I said before:

It seems like it would be the resonance of the atom that determines the point where a photon would be absorbed and that would define the difference in energy levels.  Not the other way around, which is the difference in energy levels determines if a photon is absorbed and that defines the resonance because it doesn't make sense that way.  It's putting the cart before the horse.

Right, as a function of mass and bond strengths which determine both resonance and energy levels.

studiot has covered this. In the systems we are discussing, resonance is when two different things match in frequency (energy of the photon, and energy level difference in the atom). But the energy structure of an atom or molecule does not rely on this, and is not because of vibration. i.e. it's not a ball on a spring. 

 

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1 hour ago, swansont said:

studiot has covered this. In the systems we are discussing, resonance is when two different things match in frequency (energy of the photon, and energy level difference in the atom). But the energy structure of an atom or molecule does not rely on this, and is not because of vibration. i.e. it's not a ball on a spring. 

Well more modestly I've introduced this.

I had been going to cover it more thoroughly.

When a molecule has more than one bonding mode or configuration available to it, very often a phenomenon occurs that chemists call 'resonance'.

This occurs when the result lowers the internal energy of the molecule compared to any of the modes referred to above.

Essentially what happens is that a combination of the different modes actually occurs.

When this does occur the energy difference between the non hybrid structure and others is called the 'resonance energy'.

In the case of carbon dioxide there are three contender molecular structures which combine to form the actual one.

There are no vibrations and therefore no frequency associated with this and the molecule is in this state, whether it is vibrating in sympathy with some other input or not.

Since (as I have already indicated) the configuration geometry of the molecule is altered by this chemical resonance, the mechanical vibration modes are also displaced from those of the simpler contributing structures.

Since this is a Chemistry question in the Chemistry section, this is what I take the term resonance to mean.

 

It is also true that, just as an conductive aerial provides a conductive path for electrical resonance to occur (in classical terms),

So the slight charge separation within the molecule provides a capacitive path for electrical resonance in the bonds of that molecule. (again in classical terms = displacement current)

Change of potential can lead to electrical work being done in distorting the bonds and thus energy being transferred to the molecule.

 

I am sorry you do not want to explore this fascinating subject, but rather chose to fight tooth and nail to bend observed phenomena to your own limited viewpoint.

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14 hours ago, studiot said:

I really don't know why I am bothering but I will spell it out in simple sentences.

  1. You have asked a Chemistry question in the Chemistry section of this forum.
  2. You insist in the above quoted definition of Resonance.
  3. I have not told you this is incorrect.
  4. I have told you that your definition is appropriate to the Physics of Mechanical vibrating systems.
  5. I have also told you that there is a separate, very different  definition in Chemistry.
  6. I have also told you that this usage has nothing to do with vibrating systems. In fact it applies to the carbon dioxide molecule whether it is vibrating or not.
  7. You have steadfastly refused to discuss this.

In these circustances I can only suggest adding Chemistry to John Cuthber's list for you to study.

I have also told you that the vibrations in question are not due to the promotion of electrons to higher energy levels.
Again in your responses you steadfastly continue to promote this fiction, as with the quoted response to swansont.

It is because you focus on ME and not the TOPIC.  I would enjoy talking to you more if I were not the subject of the conversation.  Perhaps YOU should start a topic in the psychology section ;)

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7. You have steadfastly refused to discuss this.

I do not remember steadfastly refusing to discuss anything.

Since the topic has now changed to psychology, here is the problem:

On 9/13/2017 at 4:18 PM, studiot said:

Despite your unappreciative/unhelpful remarks in your last reply to me I will try one more time to help.

On 9/14/2017 at 8:53 AM, studiot said:

I am saying it like this because you chose to simply quibble by ignoring various helpful comments I made to enliven and enrich the discussion.

On 9/15/2017 at 6:27 PM, studiot said:

Finally your response to my observation that waves are larger than the obstruction leaves much to be desired.

On 9/22/2017 at 4:01 PM, studiot said:

when I recommend forgetting resonance I also offered a reason so I was suprised you did not ask for this rather than your actual response.

On 9/25/2017 at 8:43 AM, studiot said:

But sadly I can only conclude the following from this address as the only response to an explanation, already twice given:-

I take this last bit to mean

"My mind is made up so don't confuse me with the facts"

I actually do like you, but interacting with you makes me feel like crap and the situation is out of my control because I cannot spontaneously make myself as smart as you'd like me to be.  It seems no matter what I say, you're going to find some fault in how I replied... and it's not that I'm steadfastly against improving myself, but the frequency of occurrence is approaching 100% which leads me to believe there is no way to live up to your standards and any effort is futile.

I'll concede to you that I am not the most observant person and I'm always the one who walks all over a snake without ever seeing it or makes a chess move without seeing the bishop lurking in the corner, so it's very possible I read right over a point you made and didn't see it, but for you to say my mind is made up is an offense against my character and integrity and is tantamount to calling me a liar.  It's true I tend to stick to my guns, but I will not be an example of cognitive dissonance.  If you show me evidence that I should change my mind, then I will change it and any evidence you think you have to the contrary is likely a misinterpretation on your part or perhaps a lack of perception on mine, but I assure you it is not because I am unable to be wrong.  In this thread I was wrong about gamma rays and I was wrong about thinking EMWs affected matter regardless of charge and I'm sure I'll be wrong about more things, but I can't say I'm wrong until someone shows me how I am.

14 hours ago, studiot said:

I am sorry you do not want to explore this fascinating subject, but rather chose to fight tooth and nail to bend observed phenomena to your own limited viewpoint.

I agree it is fascinating, but quite honestly, I'm considering taking the topic to another board because it has gotten too personal here and the answer you supplied, I can't make any sense of it.  Perhaps there is a language barrier.  Anyway, it's a cryptic answer and therefore the upvote indicates a tribalistic uniting against a common enemy (ie me), so that's my cue to seek greener pastures.

15 hours ago, swansont said:

studiot has covered this. In the systems we are discussing, resonance is when two different things match in frequency (energy of the photon, and energy level difference in the atom). But the energy structure of an atom or molecule does not rely on this, and is not because of vibration. i.e. it's not a ball on a spring. 

And this answer is simply a statement; not an explanation.

15 hours ago, swansont said:

Lasers do not rely on a temperature difference. Therefore, they cannot be heat.

Another statement; not explanation.  Lasers are much hotter than ambient.

15 hours ago, swansont said:

Which are consistent with each other.

I asked how you would define it and that is the best you can do?

Thanks, everyone, for your help, but I'm taking further questions to a different arena.

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8 hours ago, BanterinBoson said:

Another statement; not explanation.  Lasers are much hotter than ambient.

Oh, baloney. I've used lasers cooled below room temperature a number of times. Diode laser response is temperature dependent (the cavity length change as the material changes size) so you cool or heat laser diodes if you want to tune the wavelength. 

8 hours ago, BanterinBoson said:

I asked how you would define it and that is the best you can do?

You already quoted the definition. More than once, I think.

"Heat is the non-mechanical transfer of energy from the environment to the system or from the system to the environment because of a temperature difference between the two. "

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13 hours ago, BanterinBoson said:

It is because you focus on ME and not the TOPIC.  I would enjoy talking to you more if I were not the subject of the conversation.  Perhaps YOU should start a topic in the psychology section ;)

!

Moderator Note

We make a distinction here between people and the ideas they express. We don't attack the former, but rigor demands we attack the latter with gusto. Please re-read and apply this metric, and you'll see there is nothing personal about it. 

And if you ever feel there is, please use the Report Post feature. Civility is rule #1, but it's not uncivil to offer helpful criticism when it's needed.

 
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12 hours ago, Phi for All said:
!

Moderator Note

We make a distinction here between people and the ideas they express. We don't attack the former, but rigor demands we attack the latter with gusto. Please re-read and apply this metric, and you'll see there is nothing personal about it. 

And if you ever feel there is, please use the Report Post feature. Civility is rule #1, but it's not uncivil to offer helpful criticism when it's needed.

 

Are you saying directing the focus to me was not directing the focus to me?  I'm not clear on what you mean by "Please re-read and apply this metric, and you'll see there is nothing personal about it."  I don't want to get anyone in trouble, so it's not a big deal; I'll just move along rather than entertaining the prospect of arguing my side since there is nothing good that can come from that: either I win and get Studiot in trouble or I lose... either way, I lose.

I feel there is too much emotional involvement in this thread and it's much easier to pose the question on a different site with different people who cannot possibly be emotionally involved (yet).  It's like expecting a pay raise without needing to change employers; unfortunately, we have to bounce around to find better deals.

17 hours ago, swansont said:

Oh, baloney. I've used lasers cooled below room temperature a number of times. Diode laser response is temperature dependent (the cavity length change as the material changes size) so you cool or heat laser diodes if you want to tune the wavelength. 

I have no idea about the internals of lasers... all I know is they cut steel by melting which seems hot to me.

17 hours ago, swansont said:

You already quoted the definition. More than once, I think.

"Heat is the non-mechanical transfer of energy from the environment to the system or from the system to the environment because of a temperature difference between the two. "

So it's non-mechanical?  Are lasers mechanical?  They would have to be in order to do work, as you said before.

What about the definition regarding entropy?

What about the definition saying the only distinction between heat and work is direction?

Simply saying they are all correct does not help me.

10 hours ago, John Cuthber said:

Actually, lasers are just about the only thing you can get with a negative thermodynamic temperature.

Very cool indeed.

Cool as in cool or cool as in cool?

Negative temperatures are hotter than any positive temperatures.

 

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5 hours ago, BanterinBoson said:

 I have no idea about the internals of lasers... all I know is they cut steel by melting which seems hot to me.

Doing work transfers energy, and that can raise the temperature. Friction does it, too.

You can use lasers to cool things down, too. It's part of what I do. We use lasers to get atoms down to a few millionths of a degree above absolute zero. Doesn't seem hot to me at all.

And this "I have no idea...all I know" seems to be a recurring theme. It might be wise to ask questions instead of making pronouncements.

5 hours ago, BanterinBoson said:

So it's non-mechanical?  Are lasers mechanical?  They would have to be in order to do work, as you said before.

Lasers aren't transferring heat.

I never said they had to be mechanical to do work. I said the energy transfer from a laser is not due to a temperature difference. Those are not remotely the same thing.

5 hours ago, BanterinBoson said:

What about the definition regarding entropy?

What about the definition saying the only distinction between heat and work is direction?

Are those definitions? "What is heat?" and "What is the definition of heat?" are not identical questions. Answers to the former are probably going to yield more information than answers to the latter, since there's more to physics than definitions.

5 hours ago, BanterinBoson said:

Simply saying they are all correct does not help me.

I'm confirming that you have gotten valid information, and somehow your confusion is my fault. 

Maybe ask better questions? Or perhaps not jump into the middle of a complex subject, and expecting you're going to be able to pick up the background as you go? People study things for years to get a handle on the nuances. You aren't going to get to the same level of understanding in a few dozen posts on a discussion board.

5 hours ago, BanterinBoson said:

Cool as in cool or cool as in cool?

Negative temperatures are hotter than any positive temperatures.

These system are not in thermal equilibrium, and applying the concept of temperature to them is a dicey proposition. 

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8 hours ago, BanterinBoson said:

Are you saying directing the focus to me was not directing the focus to me?

!

Moderator Note

Oh, please. Directing the focus to YOUR IDEAS is not directing the focus to YOU. It's. NOT. Personal.

Report posts you feel attack you personally. Responding to these notes in thread is considered off-topic.

 
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  • 3 months later...

OK another interesting topic seemingly come to an end.

Could I ask, as at least one non-expert who has been viewing this  thread with interest, could someone complete the loop?

Studiot - you proposed working through this with classical wave theory. Is it possible to finish that thinking?

Cheers guys.

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2 hours ago, druS said:

OK another interesting topic seemingly come to an end.

Could I ask, as at least one non-expert who has been viewing this  thread with interest, could someone complete the loop?

Studiot - you proposed working through this with classical wave theory. Is it possible to finish that thinking?

Cheers guys.

Sure I can dredge my memory to try and find out what I was thinking of.

:)

 

Chemtube is a free university website where you can play with animations of molecules. It's also easy to use but requires javascript.

http://www.chemtube3d.com/spectrovibcd1-CE-final.html#models

I don't know how to embed the carbon dioxide animation here so thanks if anyone can achieve that.

 

If you watch the carbon moving about between the two oxygens you can see the bonds lengthening and shortening and waving about.

This means that the charges are moving relative to one and other.

In other words charge is being displaced.

But movement of charge is another word for electric current.

It was called displacement current because the charges don't flow on and on like a river, but simply change the position in space.
The original definition of displacement current was about capacitance (as I have already mentioned in this thread) and referred to how a 'current' can pass through the space between the plates of a capacitor.
It may occur only once or it may happen periodically.

 

I also said backalong in this thread that the molecules respond to the electric component of the radiation, rather like a radio antenna albeit capacitively not conductively.

Would you like to explore this further and have you any arising questions so far?

 

 

 

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Apologies on the delayed response - Studiot, plenty of things arising, lol.  I need to wrap my head around the info before asking for expansion. back at work, with exams cominng means I'm a bit time poor.

Just wanted to say thanks for now.

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  • 3 weeks later...
On 1/7/2018 at 10:07 PM, studiot said:

Sure I can dredge my memory to try and find out what I was thinking of.

:)

 

Chemtube is a free university website where you can play with animations of molecules. It's also easy to use but requires javascript.

http://www.chemtube3d.com/spectrovibcd1-CE-final.html#models

I don't know how to embed the carbon dioxide animation here so thanks if anyone can achieve that.

 

If you watch the carbon moving about between the two oxygens you can see the bonds lengthening and shortening and waving about.

This means that the charges are moving relative to one and other.

In other words charge is being displaced.

But movement of charge is another word for electric current.

It was called displacement current because the charges don't flow on and on like a river, but simply change the position in space.
The original definition of displacement current was about capacitance (as I have already mentioned in this thread) and referred to how a 'current' can pass through the space between the plates of a capacitor.
It may occur only once or it may happen periodically.

 

I also said backalong in this thread that the molecules respond to the electric component of the radiation, rather like a radio antenna albeit capacitively not conductively.

Would you like to explore this further and have you any arising questions so far?

 

 

 

Studiot

Hope you are still happy to talk on an old thread. Let me try to pull together what I think I have picked up so far.

A molecule's reaction to EM depends on it's structure, shape and bonding. CO2 is a linear molecule so it's vibrations are waggling and stretching. These motions make it unresponsive to the visible spectrum but responsive to IR. Non-linear molecules don't react to IR (but do react to visible light?) - which covers water. I would however have thought that nitrogen and oxygen were also linear?

Specifically to CO2 there are three frequencies - am I reading that graph correctly? Asymmetric being something close to 3900-3400; symmetric 2400 and bending 900?

Can those frequencies be related to the vibration modes called waggling and stretching?

I follow part only on the resonance discussion - the aerial analogy doesn't help me as my understanding of an aerial is as rudimentary as molecular vibration. Though I note the discussion that the increased energy is not related to electron states - without following this too closely, it would then relate to movement between parts of the molecule - ie the bonding.

Anyway, hope you have your red pen ready.

[ps to the many other posters here, I am not ignoring your content which has also been very interesting. Fire away at will! I am just going to avoid flights of fancy such as arguing about waves in the in absence of a medium, etc. Studiot has laid out a path that connects with me is all.]

EDIT: in the chem tube pictorial of CO2 vibration, the graph indicates several specific levels that I take to be energy levels ie VB = 0; v = 1; v = 3; Dissociation. I had thought this to be like electron energy levels, in steps, but clearly NOT electrons. Do the vibrations come in energy steps also? And does dissocation mean what it says? I would have that would require extraordinary energy but the step doesn't look huge.

 

Edited by druS
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