Are the excited atoms in radioisotopes free from unexcited atoms in radioisotopes?
Peruse the paper published in Brazilian Journal of Physics in March 2010 and see for 'new atomic state of solids (radioisotopes and XRF sources)'
Is your question about the specific activity of I-131? i.e. the ratio between radioactive (I-131) and stable (I-127) iodine?
Please take a look at (=read): http://en.wikipedia.org/wiki/Isotopes_of_iodine
http://en.wikipedia.org/wiki/Iodine-131
http://en.wikipedia.org/wiki/Fission_product_yield
http://www.nordion.com/documents/products/I-131_Solu_Can.pdf
and rephrase your question.
Jacek Koziorowski, I am not asking about the well known specific activity. It is known that 131-I is an excited atom. But, is it a free atom? Please peruse the above cited paper on new atomic state of solids (radioisotopes and XRF sources)
I-131 is a n radioactive / unstable atom; not an excited atom.
All nuclides (=isotopes) have the same chemical properties;
thus I-131 is exactly as I-127 in any chemical condition/state. Iodine exist as a molecule; I2. "free" iodine is either as a free radical I*, or as iodide ion I- or as positive ion in+1,+3,+5,+6
http://en.wikipedia.org/wiki/Iodine
There's no observable KIE (http://en.wikipedia.org/wiki/Kinetic_isotope_effect )
for iodine isotopes.
I have problems to understand the question, because my knowlege resembles Jacek´s remarks. Radioactivity of course is a matter of nucleus, not of atomic shell. Could someone please help me to get access to the problem?
Jacek Koziorowski and Hanno Krieger, Thanking you both for nice interaction. For the first time, I have experimentally detected light emission dominant in UV (more than 83% in gross light intensity) from radioisotopes including 131-I. We know from familiar atomic spectroscopy that atomic emission takes place from Na atom only when Na gets free from Cl atom in NaCl. Likewise, it is understood that the excited 131-I atom can emit light only when it gets free from unexcited sodium atom in 131-I labelled Sodium Iodide. The 131-I is termed excited atom when it emits beta and gamma radiations.
Also please peruse excerpts from page 43 in my paper:
B. Atomic state of solid sources
Radioisotopes and XRF sources giving rise to high-energy atomic spectra of excited atoms has been confirmed by both the optical techniques (Figs.1 & 3). On the basis of atomic spectra of radioisotopes and XRF sources it is reasonable to believe the existence of free atoms in analogy to the thermally excited atoms in gaseous phase causing the basic atomic spectra [9, 10]. Mainly, during excitation to optical levels the excited atom may act as free atom without any bondage from surrounding unexcited atoms in a radioisotope or XRF source. Most importantly, formation of free atoms at room temperature owes to the generation of exciting energies within excited atoms, in wide contrast to the case of thermal energies from an external source in basic atomic spectra. For example, the 0.0 080 278 MeV (Cu Ka1 X-ray) produced exciting
energy is mainly responsible for formation of free Cu atoms in Cu XRF source at room temperature. The excited free Cu atoms lying in between unexcited Cu atoms return to ground state not immediately following Cu X-ray emission but after the successive atomic emission of light. Similarly, in metal 57Co source, the 0.1221 MeV (g) produced exciting energy is mainly responsible for formation of free 57Co atoms, surrounded
by unexcited Co atoms, as shown in Fig.4. In comparison, low abundant (33.4%) Fe Ka1 X-ray energy fails to compete equally with 0.1221 MeV (g) in generating the free
atoms in required number. Excited free 57Co atom returns to ground state as an unexcited Co atom not immediately after gamma and , and Fe X-ray emissions but after atomic emission of light (Fig.1, Table I). Formation of free atoms within solid radioisotopes and XRF sources implies existence of temporary atomic state of solids, regardless of temperature [3]. The duration of free atomic state is limited to valence excitation to optical levels resulting into fluorescence light emission. The free atoms behaving differently from thermally excited atoms in gaseous phase in basic spectroscopy are responsible for a new class of room temperature atomic emission spectra of solid radioisotopes and XRF sources.
Reference:
M.A.Padmanabha Rao,
UV dominant optical emission newly detected from radioisotopes and XRF sources,
Braz. J. Phy., 40, no 1, 38-46,2010.
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-97332010000100007
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-97332010000100007
Article The first research paper in the history of science that clai...
You will see light in Na[131-I]I (sodium iodide); it is called: "Cerenkov" or "Cherenkov"
radiation.
Jacek Koziorowski , Cerenkov radiation is not emitted from 131-I in sodium iodide labelled with 131-I or any other radioisotope like 137-Cs. Cerenkov radiation is predominant in blue color and needs transparent medium. Radioisotopes and XRF sources that I have tested are solids opaque to light. I have arrived at a clear understanding that radioisotopes and XRF sources causes a new class of atomic emission spectra from UV dominant optical radiation emission newly detected from cobalt metal present as 57-Co unprecedented at room temperature.
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