[oem7110]

I would like to know on what the vibration spectrum frequency is for CO2.
Is there any online reference to check the vibration spectrum frequency for following elements?

• Carbon Dioxide
• Nitrogen
• Oxygen
• Argon
• Hydrogen
• Helium
• Methane

Does anyone have any suggestions?
Thanks in advance for any suggestions

[Irlanur]

just google IR or Raman Spectrum...

what vibration would you like to see for argon or helium?

[jpmann]

You can directly calculate the vibrational modes through the point group symmetry of the molecule of interest. A revisit of any undergraduate level text book is recommended based on your question re vibrational states of a monatomic species.

[lansuminc]

For CO2 see:
http://webbook.nist.gov/cgi/cbook.cgi?ID...
For methane see:
http://en.wikipedia.org/wiki/Methane_(da...

Ar and He are monatomic ie no bonds, no vibration, no ir spectrum.
N2, O2 and H2 have only a stretching fundamental mode which shows no dipole change so no spectrum.

[Borek]

For CO2 see:
http://webbook.nist.gov/cgi/cbook.cgi?ID...
For methane see:
http://en.wikipedia.org/wiki/Methane_(da...

Both links are broken.

[billnotgatez]

http://nvlpubs.nist.gov/nistpubs/jres/049/2/v49.n02.a04.pdf

Quote from: lansuminc

Ar and He are monatomic

no ir spectrum

I am confused

[mjc123]

By "no ir spectrum" he meandt of course "no vibrational spectrum" because there are no bonds to vibrate and absorb energy in the IR region. However, you do get atomic emission spectral lines in the IR due to transitions between higher electronic states. Think of the well known hydrogen emission lines with E = R(1/n₁² - 1/n₂²). The Lyman series (n₁ = 1) is in the UV; Balmer (n₁ = 2) in the visible, Paschen, Brackett etc. in the IR. Generally, the energy difference between ground state and excited states is such that atomic absorption spectra occur in the visible or UV - so noble gases won't give an ir absorption spectrum.

[billnotgatez]

Thanks for the clarification