When you look at absortion lines of light....

  • Thread starter Nicholas Lee
  • Start date
  • Tags
    Light Lines
In summary, in the absorption and emission spectrum of elements, there is a lot of colored light that is not absorbed by carbon. This means that some of the light is able to pass through a four inch block of carbon, as carbon is not able to absorb all wavelengths of blue light. The same concept applies to other elements and their absorption and emission spectra. A solid black object would absorb all visible wavelengths, so there would be no emission lines on a chart for that object.
  • #1
Nicholas Lee
27
1
in the absorption and emissions spectrum of elements, what happens to the light that is not absorb?

-ed.
in the absortion and emission spectrum of elements, in carbon there is a lot of colored light that carbon does not absorb.
Like carbon absorbs blue light, but not all wavelengths of blue light.
So what happens to all this colored light that does not get absorbed by carbon.
Say in a four inch cubed block of carbon what is happening to the colored light that's not being absorbed, and emissioned by the carbon electrons, some of the colors of light have to be getting transmission through the four inch block of carbon.
Whats really happening.
Thank you for you help with this question, anything helps even a few words.
 
Physics news on Phys.org
  • #2
I'm no expert but usually absorption and emission spectra are separate.

When carbon absorbs some blue light, what does not get absorbed reaches your detector.
If carbon emits blue light, then that light is what reaches your detector.
absemm.jpg


I don't know about examining light that is first absorbed then emitted.
 
  • #3
Carbon isn't special in this sense , all elements absorb or emit EM at certain wavelengths.
A low frequency form of EM, say radio frequency, would not be absorbed (much) by a four inch block of carbon.
X-rays would be though. The carbon will get hot.
 
  • #4
DaveC426913 said:
I'm no expert but usually absorption and emission spectra are separate.

When carbon absorbs some blue light, what does not get absorbed reaches your detector.
If carbon emits blue light, then that light is what reaches your detector.
absemm.jpg


I don't know about examining light that is first absorbed then emitted.
DaveC426913 said:
I'm no expert but usually absorption and emission spectra are separate.

When carbon absorbs some blue light, what does not get absorbed reaches your detector.
If carbon emits blue light, then that light is what reaches your detector.
absemm.jpg


I don't know about examining light that is first absorbed then emitted.
when you meant detector did you mean, some of the light blue, light that carbon does not absorb, would get transmission through the carbon, and be detectable on the other side.
Glassy_carbon_and_a_1cm3_graphite_cube_HP68-79.jpg
 
  • #5
Nicholas Lee said:
Does some of this blue light get transmitted through the carbon.
carbon cube example below.
A solid does not behave like a collection of individual atoms. The absorption spectrum of a bloc of carbon has nothing to do with the atomic spectrum of carbon. Case in point: do diamond and graphite have the same color?
 
  • #6
DrClaude said:
A solid does not behave like a collection of individual atoms. The absorption spectrum of a bloc of carbon has nothing to do with the atomic spectrum of carbon. Case in point: do diamond and graphite have the same color?
So the absortion, and emission spectrum in this diagram is for carbon gas, and not carbon solid.

.https://mail.google.com/mail/u/0/?ui=2&ik=1a702d60a0&view=fimg&th=152423f8a01db4f4&attid=0.1&disp=emb&realattid=73f0543dd772c52d_0.1&attbid=ANGjdJ9q09cDCkalqGztvo2O9NW7YSxShK7zdZsbTlFAEs1qToCzxd-S9r_jPJ1e239hldvDmzPzUyzHx8R1xnuhsodAFXWCDDyNseVPV_wroPMKiHBd0ajUZHHGsxs&sz=w496-h406&ats=1452897686667&rm=152423f8a01db4f4&zw&atsh=1
Maybe this diagram above was the absorption, and emission spectrum for carbon gas, so here in the diagram below is a diagram for the emission of iron, hopefully solid iron because it takes a lot of energy to turn iron to a gas.
If you notice there is a large gap in the blue, and red emission chart for iron, (hopefully solid iron).
So does this mean *some* of that wavelength of blue, and red light does get transmission through a four inch solid cubed piece of iron.
So all this blue, and red colored light has to do is pass through four inches of solid iron, the blue, and red light does not need to pass through any more thicker iron material more than four inches.
https://mail.google.com/mail/u/0/?ui=2&ik=1a702d60a0&view=fimg&th=15247719d336dd43&attid=0.1&disp=emb&realattid=ii_1524759e5a833243&attbid=ANGjdJ-mKebm2LDhl5c3tLdKMu6gDJ88PeuRfZHPDH92xitV0pQWB__mhZ_kaG5kUgu-fjL8IHEKDNaiDDSmAvbzhcq84evYloSDoB1NwIqm3fPupnNn9nSgiYwUYsI&sz=w1000-h392&ats=1452897686754&rm=15247719d336dd43&zw&atsh=1
Thank you for your help Dr Claude.
 
Last edited:
  • #7
Nicholas: we are not seeing any of your images. The URLs you are suing appear to be a PHP proxy to images. You need to provide the URL to the actual images.
 
  • #8
DaveC426913 said:
Nicholas: we are not seeing any of your images. The URLs you are suing appear to be a PHP proxy to images. You need to provide the URL to the actual images.
Okay, sorry here you go here the link,
http://astrobob.areavoices.com/2010/03/25/how-we-wondered-what-you-were-and-now-we-know/
Its the fourth image from the top.
Spectra_emission_hydrogen_andiron.jpg

The fingerprints of hydrogen (top) and iron when they emit light after being energized by heating. Iron has many more lines because it’s a much more complicated element than hydrogen with 26 protons and 26 electrons compared to hydrogen’s one proton and one electron.
 
  • #9
Nicholas Lee said:
Okay, sorry here you go here the link,
http://astrobob.areavoices.com/2010/03/25/how-we-wondered-what-you-were-and-now-we-know/
Its the fourth image from the top.
Spectra_emission_hydrogen_andiron.jpg

The fingerprints of hydrogen (top) and iron when they emit light after being energized by heating. Iron has many more lines because it’s a much more complicated element than hydrogen with 26 protons and 26 electrons compared to hydrogen’s one proton and one electron.
Also how come I can see the images.
 
  • #10
Nicholas Lee said:
Okay, sorry here you go here the link,
http://astrobob.areavoices.com/2010/03/25/how-we-wondered-what-you-were-and-now-we-know/
Its the fourth image from the top.
Spectra_emission_hydrogen_andiron.jpg

The fingerprints of hydrogen (top) and iron when they emit light after being energized by heating. Iron has many more lines because it’s a much more complicated element than hydrogen with 26 protons and 26 electrons compared to hydrogen’s one proton and one electron.
OK, I'm seeing this one.
 
  • #11
DaveC426913 said:
OK, I'm seeing this one.
Thank you so much for your answer, just 2 follow up questions.
Maybe that was the absorption, and emission spectrum for carbon gas, so here in the diagram below is a diagram for the emission of iron, hopefully solid iron because it takes a lot of energy to turn iron to a gas.
If you notice there is a large gap in the blue, and red emission chart for iron, (hopefully solid iron).
So does this mean *some* of that wavelength of blue, and red light does get transmission through a four inch solid cubed piece of iron.
So all this blue, and red colored light has to do is pass through four inches of solid iron, the blue, and red light does not need to pass through any more thicker iron material more than four inches.
https://mail.google.com/mail/u/0/?ui=2&ik=1a702d60a0&view=fimg&th=15247719d336dd43&attid=0.1&disp=emb&realattid=ii_1524759e5a833243&attbid=ANGjdJ9BDdHe7XaRL2kFnoX2tFxFNXO_rAXzwllJA_lPB-bGVPfQp4yz8I_Cd4mD3LkDkPJk0_kaB4Ul9dDDvNDqbK63hwYf9m03drNwwKIpcaapbfsOVXFFJ_f5HkQ&sz=w1000-h392&ats=1452898970312&rm=15247719d336dd43&zw&atsh=1
2. So you said "a solid black object would absorb all visible wavelengths", so there would be no emission lines on a chart for a solid black object, because solid black absorbs all wavelengths of light is this correct?
Thank you very much for your help.
 
  • #12
Nicholas Lee said:
Also how come I can see the images.
You are logged in with your account at google. We are not.
All those absorption lines are for gases, including iron. It takes a lot of energy to turn it into a gas, but it takes even more energy to excite those lines.

Solid iron, as a metal, will reflect most visible light and absorb the rest. No transmission if your sample is thicker than a few ten micrometers.
Nicholas Lee said:
So you said "a solid black object would absorb all visible wavelengths", so there would be no emission lines on a chart for a solid black object, because solid black absorbs all wavelengths of light is this correct?
The opposite: the absorption plot would be completely black (as everything is absorbed), the emission part would be completely full with colors (as everything is emitted if the material is hot enough).From this thread:
Nicholas Lee said:
Great, thank you for your answer, you said" Graphite will absorb MOST visible light not all" if you meant MOST then there are some wavelengths of light that transsmission through the graphite right.
No transmission, just some reflection at the surface. Everything that is not reflected gets absorbed.
 
  • #13
mfb said:
You are logged in with your account at google. We are not.
All those absorption lines are for gases, including iron. It takes a lot of energy to turn it into a gas, but it takes even more energy to excite those lines.

Solid iron, as a metal, will reflect most visible light and absorb the rest. No transmission if your sample is thicker than a few ten micrometers.
The opposite: the absorption plot would be completely black (as everything is absorbed), the emission part would be completely full with colors (as everything is emitted if the material is hot enough).From this thread:
No transmission, just some reflection at the surface. Everything that is not reflected gets absorbed.
Great, thank you for you answer that explains it all thank you.
 
  • Like
Likes mfb
  • #14
To move from a lower to a higher energy level, an electron must gain energy. Oppositely, to move from a higher to a lower energy level, an electron must give up energy. In either case, the electron can only gain or release energy in discrete bundles.

Now let's consider a photon moving toward and interacting with a solid substance. One of three things can happen:

  1. The substance absorbs the photon. This occurs when the photon gives up its energy to an electron located in the material. Armed with this extra energy, the electron is able to move to a higher energy level, while the photon disappears.
  2. The substance reflects the photon. To do this, the photon gives up its energy to the material, but a photon of identical energy is emitted.
  3. The substance allows the photon to pass through unchanged. Known as transmission, this happens because the photon doesn't interact with any electron and continues its journey until it interacts with another object.
Glass, of course, falls into this last category. Photons pass through the material because they don't have sufficient energy to excite a glass electron to a higher energy level. Physicists sometimes talk about this in terms of band theory, which says energy levels exist together in regions known as energy bands. In between these bands are regions, known as band gaps, where energy levels for electrons don't exist at all.

Some materials have larger band gaps than others.

Glass is one of those materials, which means its electrons require much more energy before they can skip from one energy band to another and back again. Photons of visible light -- light with wavelengths of 400 to 700 nanometers, corresponding to the colors violet, indigo, blue, green, yellow, orange and red -- simply don't have enough energy to cause this skipping.

Consequently, photons of visible light travel through glass instead of being absorbed or reflected, making glass transparent.

At wavelengths smaller than visible light, photons begin to have enough energy to move glass electrons from one energy band to another. For example, ultraviolet light, which has a wavelength ranging from 10 to 400 nanometers, can't pass through most oxide glasses, such as the glass in a window pane. This makes a window, including the window in our hypothetical house under construction, as opaque to ultraviolet light as wood is to visible light.If an electron is in the first energy level, it must have exactly -13.6 eV of energy. If it is in the second energy level, it must have -3.4 eV of energy.

Let's say the electron wants to jump from the first energy level, n = 1, to the second energy level n = 2. The second energy level has higher energy than the first, so to move from n = 1 to n = 2, the electron needs to gain energy. It needs to gain (-3.4) - (-13.6) = 10.2 eV of energy to make it up to the second energy level.

So here's the question, If an electron is in the first energy level, it must have exactly -13.6 eV of energy. If it is in the second energy level, it must have -3.4 eV of energy.
Let's say the electron wants to jump from the first energy level, n = 1, to the second energy level n = 2. The second energy level has higher energy than the first, so to move from n = 1 to n = 2, the electron needs to gain energy. It needs to gain (-3.4) - (-13.6) = 10.2 eV of energy to make it up to the second energy level.
If it takes 10 eV to move the electron in shell 2 , in the glass, and the iron block, then why does the glass electron not get excited when hit by a photon.
Why is the iron electron absorbing.
What makes a four inch cubed block of glass different to a four inch cubed block of opaque solid iron, what is the difference in the glass, and irons electrons, why is the glass block allowing transmission, and the iron block absorbing.
Is it the amount of electrons in the shells in the iron, or is it the electrons in the glass need more eV compared to the irons electrons.
What I am trying to do is find all the ways the electron in the atom can not be excited, by light, or any type of EM radiation, or another way to look at it is, how the electron can be kept in the ground state shell 1 the "1 shell" (also called "K shell"), and not get excited to shell 2.
https://mail.google.com/mail/u/0/?ui=2&ik=1a702d60a0&view=fimg&th=15247bba1386a248&attid=0.2&disp=emb&realattid=ii_15247bad4c5acd4e&attbid=ANGjdJ_gB_S7X_IC6st087aolohQiGHeOtNC_3il-P0E4z3F-CUQOQR_q43rRRsTIDqe_YlK2AlLrjWiYTkFRSctQkU5Znv7P5E6sZNIDv5Yz6cBpDC4rbnb5uu7Avs&sz=w746-h320&ats=1452905705409&rm=15247bba1386a248&zw&atsh=1
Thank you for your help.
 
  • #15
Oh God please stop pressing the Post Reply button.
 
  • #16
Nicholas Lee said:
If an electron is in the first energy level, it must have exactly -13.6 eV of energy. If it is in the second energy level, it must have -3.4 eV of energy.
Those numbers apply to atomic hydrogen only. They are different for everything else. Every material has different energy levels.

Photons of visible light have an energy of about 1.5 to 3 eV.
 

FAQ: When you look at absortion lines of light....

What are absorption lines of light?

Absorption lines of light are dark lines that appear in the spectrum of light when it passes through a medium, such as a gas or a liquid. These lines are caused by the absorption of specific wavelengths of light by the atoms or molecules in the medium.

How are absorption lines used in scientific research?

Absorption lines are used to identify the elements present in a medium, as each element has a unique set of absorption lines. By analyzing the position and intensity of these lines, scientists can determine the composition and properties of the medium.

What is the significance of studying absorption lines?

Studying absorption lines can provide valuable information about the physical conditions and processes happening in a particular medium. This can help scientists understand the formation and evolution of galaxies, stars, and other astrophysical objects.

Can absorption lines be used for other purposes besides astronomy?

Yes, absorption lines can also be used in other fields such as chemistry and environmental science. In chemistry, they can be used to identify and study the properties of different chemical compounds. In environmental science, they can be used to analyze the composition of gases in the atmosphere.

How are absorption lines different from emission lines?

The main difference between absorption and emission lines is the direction of light. Absorption lines appear as dark lines in a spectrum because the light passing through a medium is absorbed, while emission lines appear as bright lines because the atoms or molecules in a medium emit light at specific wavelengths.

Back
Top