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Partly radiogenic?
editWould it not be more correct to refer to some isotopes as only "partly radiogenic in origin"? For example the article now describes N-14 as radiogenic because some N-14 is formed from C-14, but I assume most terrestrial N-14 is primordial. Also some of the terrestrial abundance of Pb isotopes is primordial. Dirac66 (talk) 16:03, 9 August 2010 (UTC)
- Yes, of course. Pb-204 is entirely primordial and is used to estimate the fraction of the other isotopes that are also primordial. So Pb-206, 207, and 208 are all only partly primordial, in rocks that contain uranium and thorium. The parts of each of of the last three that aren't primordial, are radiogenic decay products of U-238, U-235, and Th-232, respectively. SBHarris 18:00, 9 August 2010 (UTC)
- The article is much better now. I reworded one paragraph for clarity, hopefully without changing your meaning. Dirac66 (talk) 23:42, 9 August 2010 (UTC)
Time unit prefixes should be uniform.
editThe table lists half-lives with mixed prefixes - English (Byr = billion year) and Greek (kyr = kiloyear), and Myr could be either million or mega. Can we be uniform with Gyr, Myr and kyr? After the first Gyr we could add (109 yr) in parentheses to help the least numerate readers? Dirac66 (talk) 13:49, 7 August 2011 (UTC)
- P.S. Billion is often avoided in science because it traditionally meant 109 in North America and 1012 in Britain and Europe. Giga is unambiguous. Dirac66 (talk) 13:52, 7 August 2011 (UTC)
Heat
editWhat is the nature of the heat which produced from the decay? Infra-red? Gamma waves which ionize other atoms thus indirectly leading to IR? Some other type of electromagnetic radiation? Or something else completely? BigSteve (talk) 08:55, 9 March 2014 (UTC)
- The radioactive decay steps leading to these nuclides are alpha decay and beta decay, so the energy is initially released as kinetic energy of emitted alpha and beta particles. These fast particles are then slowed down in collisions with various atoms and molecules and ions, which can be excited in many ways. So the initial kinetic energy is distributed into many modes of excitation, which is equivalent to heat. Electromagnetic energy is not usually involved at all here. Dirac66 (talk) 20:57, 9 March 2014 (UTC)