- #1
fog37
- 1,568
- 108
Hello Forum,
I am confused about the concept of rotational energy levels, electronic energy levels, and vibrational levels. A graph of "Energy versus Distance" is usually presented and the various horizontal bars represent the energy levels, which are simply energy amounts.
The energy of a molecule/atom or system of atoms/molecules can be decomposed in 3 parts: rotational, vibrational and electronic energy (translational energy should also be included).
Some books explain that the vibrational levels are indexed for each electronic state while rotational levels are indexed only for one vibrational state...What does that really mean?
This is how I envision it: when a molecule absorbs energy from an external source its outer electron may remain in the ground state while the molecule is vibrating/rotating at the same time (i.e. the molecule is in an excited rotational/vibrational state) or the electrons may be in an excited state while the whole molecule is also rotating and/or vibrating...
Am I on the right track?
Thanks,
Fog37
I am confused about the concept of rotational energy levels, electronic energy levels, and vibrational levels. A graph of "Energy versus Distance" is usually presented and the various horizontal bars represent the energy levels, which are simply energy amounts.
The energy of a molecule/atom or system of atoms/molecules can be decomposed in 3 parts: rotational, vibrational and electronic energy (translational energy should also be included).
- Rotational energy is associated to the rotation of the entire structure of the molecule (nuclei+electrons).
- Vibrational energy is associated to the vibration of the entire molecule.
- Electronic energy refers to the excitation of the electrons inside the molecule only.
Some books explain that the vibrational levels are indexed for each electronic state while rotational levels are indexed only for one vibrational state...What does that really mean?
This is how I envision it: when a molecule absorbs energy from an external source its outer electron may remain in the ground state while the molecule is vibrating/rotating at the same time (i.e. the molecule is in an excited rotational/vibrational state) or the electrons may be in an excited state while the whole molecule is also rotating and/or vibrating...
- The rotational energy levels represents the discrete (quantized) energies associated to the molecule or atom when the it is rotating, correct?
- How about electronic energy levels? Do those electronic energies correspond to the energies associated with electrons when they are excited inside atoms or molecules?
- The vibrational energy levels correspond to the energy that a molecule/atom has due to its vibrational motion (state), correct?
Am I on the right track?
Thanks,
Fog37