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Author Topic: Could heavier elements be formed in a massive enough star?  (Read 1675 times)

system

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Given that the heaviest elements are forged during a supernova event, is it theoretically possible that there could be heavier naturally occurring elements that we don't know about if there was a star massive enough to forge them? 
Asked by Tom Ristola

                                       
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« Last Edit: 25/03/2011 18:30:03 by _system »


 

Offline Soul Surfer

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Could heavier elements be formed in a massive enough star?
« Reply #1 on: 26/03/2011 09:30:08 »
An element is defined by the composition of it nucleus.  The all important addition to the question is Are you only counting "stable" nuclei or those with half lives longer than some reasonable human scale limit.  That is long enough to have their chemical properties as an element investigated before they decay?  Elements would have to come into this category for them to be included as "naturally occuring"  because of the long time period between their being forged and us detecting them.

The exception of course are those elements that are being manufactured in the laboratory.  but more of that later.

If you don't put this limit on there are all sorts of short lived elements to consider.

The truth is that we almost certainly know all the stable elements that can exist.  Towards the end of the periodic table all the elements are radioactive that is their nuclei decay after some time into a smaller and more stable nucleus.  Making further elements in the laboratory by irradiating nuclei with other nuclei in the hope that they will fuse had form more complex nuclei only produces lest stable elements with one exception.  There is what is called am "island of stability" because the structure reaches complete shells and is more stable.  this is currently being investigated and although the  elements are more stable it does not seem likely that there are any fully stable elements are there.

Tho return to the creation of these elements in stars.  Once you get beyond iron in the periodic table it costs energy to make the elements.  This is why we can build nuclear reactors to gain energy by splitting uranium atoms into smaller atoms.  So the creation of heavy nuclei saps the stars energy and contributes to the final collapse.  This probably occurs during the final stages of the life of a star before it undergoes its terminal collapse and bounce to become a supernova  and leave behind a neutron star or a black hole
 

Offline Novacaine

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Could heavier elements be formed in a massive enough star?
« Reply #2 on: 26/03/2011 13:15:45 »

As far as I know, the elements heavier than iron need so much more energy than a star can produce. Those heavier elements can only be produced by a supernova explosion.   
 

Offline chris

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Could heavier elements be formed in a massive enough star?
« Reply #3 on: 26/03/2011 14:36:53 »
There are postulated to be so-called "islands of stability" for nuclei beyond atomic number 120; is it possible that, on rare occasions, odd massive stable atoms are made in a supernova that fall within these realms but are not detected owing to their rarity?

Chris
 

Offline Bored chemist

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Could heavier elements be formed in a massive enough star?
« Reply #4 on: 26/03/2011 15:44:02 »
If you have a neutron star, and a single proton falls onto it, leaving the electron in orbit, is it a stupidly heavy isotope of hydrogen?
 

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Could heavier elements be formed in a massive enough star?
« Reply #4 on: 26/03/2011 15:44:02 »

 

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