Absorption and emission spectroscopy of atoms

In summary, the conversation discusses the differences in spectroscopic absorption and emission between isotopes of the same atom and isotopes of different atoms. While changing the number of protons and electrons in an atom has a significant impact on its coarse structure, changing the number of neutrons in the nucleus affects the atom's spectrum at the hyperfine level. The latter effect is smaller in comparison.
  • #1
MartinG
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4
Hello !

As I understand it, the different isotopes of the same atom have a slightly different spectroscopic absorption and emission where, for example, Deuterium absorbs slightly shorter wavelengths than Protium.

My question is if two isotopes of different atoms, for example Tritium and Helium 3, which have three nucleons in both atoms, the spectroscopic absorption and emission of the different Isotopes is the same or different?

I thank you in advance for your responses.
 
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  • #2
The primary interaction in an atom is Coulombic. The effects of the mass of the heavier nucleus is predominately to alter the "reduced mass" $$\mu=m_e\frac 1 {1+\frac {m_e} {m_{nucleus}}}$$This is small and easy.
The other effects, which change nucleic charge (and electron number), affect all aspects of the interaction and produce major changes to the calculation and its outcome
 
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  • #3
MartinG said:
My question is if two isotopes of different atoms, for example Tritium and Helium 3, which have three nucleons in both atoms, the spectroscopic absorption and emission of the different Isotopes is the same or different?
Very different.

Changing the number of protons and/or electrons in an atom will change it's coarse structure (at the level where even the Bohr model can predict a change). These changes are of order 0.1 - 1eV. Changing the number of neutrons in the nucleus changes the atom's spectrum at the hyperfine level (caused by magnetic interactions between the nuclear spin and the electrons' orbit and spin). These changes are at the level of 0.00001 - 0.0001 eV.
 
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  • #4
Helium nuclei have twice the charge, which scales all energy levels with a factor 4. Instead of -13.6 eV the lowest energy state is now at about -54 eV. That's far more important than the relatively small isotope effect.
 
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Related to Absorption and emission spectroscopy of atoms

1. What is absorption and emission spectroscopy?

Absorption and emission spectroscopy is a technique used in scientific research to study the interaction of light with atoms. It involves measuring the absorption or emission of light by atoms to determine their energy levels and properties.

2. How does absorption spectroscopy work?

In absorption spectroscopy, a beam of light is passed through a sample of atoms. The atoms absorb specific wavelengths of light, which are then measured by a detector. The resulting absorption spectrum can be used to identify the atoms present and their concentrations.

3. What is the difference between absorption and emission spectroscopy?

The main difference between absorption and emission spectroscopy is the direction of light flow. In absorption spectroscopy, light is absorbed by the atoms, while in emission spectroscopy, light is emitted by the atoms. Additionally, absorption spectroscopy is used to study the properties of atoms, while emission spectroscopy is used to study the properties of light.

4. What are the applications of absorption and emission spectroscopy?

Absorption and emission spectroscopy have a wide range of applications in various fields such as chemistry, physics, and astronomy. They are used to study the composition, structure, and properties of atoms, molecules, and other materials. They are also used in environmental monitoring, forensic analysis, and medical diagnostics.

5. How is absorption and emission spectroscopy used in the study of atoms?

In the study of atoms, absorption and emission spectroscopy are used to determine the energy levels of atoms, their electronic configurations, and their interactions with other atoms or molecules. This information is crucial for understanding the behavior and properties of atoms and for developing new technologies and materials.

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