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Internal conversion is an atomic decay process where an excited nucleus interacts electromagnetically with one of the orbital electrons of an atom. This causes the electron to be emitted (ejected) from the atom. [1] [2] Thus, in internal conversion (often abbreviated IC), a high-energy electron is emitted from the excited atom, but not from the ...
Bimolecular electron transfer always produces a reactive chemical species, free radicals. [citation needed] Nucleic acids (precisely the single, free nucleotides, not those bound in a DNA/RNA strand) have an extremely short lifetime due to a fast internal conversion. [3] Both melanin and DNA have some of the fastest internal conversion rates.
The Hager-Seltzer calculations omit the M and higher-energy shells on the grounds (usually valid) that those orbitals have little electron density at the nucleus and can be neglected. To first approximation this assumption is valid, upon comparing several internal conversion coefficients for different isotopes for transitions of about 100 keV.
An isomeric transition or internal transition (IT) is the decay of a nuclear isomer to a lower-energy nuclear state. The actual process has two types (modes): [24] [25] γ (gamma ray) emission (emission of a high-energy photon), internal conversion (the energy is used to eject one of the atom's electrons).
Usually, a gamma ray is emitted during this transition, but nuclear de-excitation may also take place by internal conversion. Following capture of an inner electron from the atom, an outer electron replaces the electron that was captured and one or more characteristic X-ray photons is emitted in this process.
The observation of electron tracks that were independent of the frequency of the incident photon suggested a mechanism for electron ionization that was caused from an internal conversion of energy from a radiationless transition. Further investigation, and theoretical work using elementary quantum mechanics and transition rate/transition ...
A corollary of Kasha's rule is the Vavilov rule, which states that the quantum yield of luminescence is generally independent of the excitation wavelength. [4] [7] This can be understood as a consequence of the tendency – implied by Kasha's rule – for molecules in upper states to relax to the lowest excited state non-radiatively.
A second type of nonradiative transition is internal conversion (IC), which occurs when a vibrational state of an electronically excited state can couple to a vibrational state of a lower electronic state. The molecule could then subsequently relax further through vibrational relaxation.