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Age of the Earth and the star that preceded the Sun

How were the heavy elements from iron to uranium made?

References: http://www.phy.anl.gov/accelerator_rd/index.html

Review of proposed Tech: http://www.annualreviews.org/doi/abs/10.1146/annurev.nucl.55.090704.151604

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Argus
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  • Heavier elements came from dying stars etc. See this question and the first answers for the detailed nuclear processes by which various elements were born: http://physics.stackexchange.com/questions/3833/age-of-the-earth-and-the-star-that-preceded-the-sun – Luboš Motl Jun 12 '12 at 06:30
  • As this question asks directly about the process that creates heavy elements it is not based on a perticular star and in fact references the possibility of research to prove this theory. – Argus Jun 15 '12 at 01:59

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The two main contributions are thought to be from the s-process and the r-process, which are both neutron capture processes that are differentiated by their speed relative beta-decay of neutron rich isotopes.

Both are end-of-stellar-life processes with the S-process probably happening in the giant stages of very heavy stars and the r-process probably happening in core-collapse supernovas.

dmckee --- ex-moderator kitten
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Unlike light elements, which release energy during fusion, elements heavier than iron require energy for their creation. This happens because the nuclear binding energy is at its maximum at iron. Hence lighter elements were made in ordinary stars, using fusion. However, heavier elements were made in supernovas, as huge amounts of extra energy are released during the explosion, some of which is used to force heavy nuclei together and create heavier elements.

hdhondt
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  • we are all children of stars, came from stardust!!! – Vineet Menon Jun 12 '12 at 07:11
  • Good start but I asked "How" not "Where" what specific amount of energy does this increase exponentially for each heavier element. – Argus Jun 12 '12 at 16:41
  • Not all and perhaps not even most heavy elements are made in supernovae. http://physics.stackexchange.com/questions/7131/origin-of-elements-heavier-than-iron-fe?lq=1 – ProfRob Jun 20 '16 at 16:34