Are their super heavy/dense stable elements we haven't discovered?

[aka1nas]

Hi all,
I was in a geography class yesterday and the prof was mentioning about how, over time, heavier elements end up towards the earth's core while lighter elements, such as silicas, end up closer to the crust. That got me thinking. Could their be any super heavy metals or other materials very deep in the mantle or core that we haven't found yet? Morever, it seems like everytime scientists discover some new element with a huge Atomic Mass number it is unstable and can only exist for a fraction of a second in normal conditions. I haven't taken chemistry or physics for several years, so I am a little fuzzy on whether or not it is possible to predict whether a certain theoretical element would be stable. Is there any reason that one cannot create super dense elements that have many more protons than the currently discovered elements on the periodic chart? Can current particle accelerators accomplish this?

 

[silverpig]

When physicists talk about creating "stable" superheavy elements what they mean is that they decay in 10^-10 seconds instead of 10^-22 seconds. Sure, it's still a blink of they eye, but it lasts a trillion times longer than the typical heavy element.

Also, all the heavy elements we have on earth (anything past iron really) was created when a star went supernova. There's just no way to make uranium naturally on earth from lighter elements. It was all there when the earth was formed.

 

[RossGr]

Simple answer is, no.

Through Quantum Theory we have a very complete understanding of atoms and atomic structure. Look at the periodic table, it does not have any holes in it. The periodic table is a graphic demonstration of how atoms are structured. It is complete, except at the end with the heaviest elements. We can predict the existance and properties of elements which we have not yet found in nature. There are no undiscoverd elements which we do not already know about.

 

[Calin]

The time span of the elements after the 100th is on the order of seconds or less. There were superheavy elements created in ultra high power accelerators that weren't really discovered but their presence identified thanks to their decomposition (fission). The average time span for those elements is sub microsecond. The energy used in the newest accelerators are much more violent that what it is found inside Earth's core, so no heavy elements are created inside.

 

[Hayabusa Rider]

Actually there are reasonable hypotheses about there being the potential for superheavy elements being as stable as "normal" ones. The problem is that there is no known way of manufacturing them, and there is certainly no mechanism for natural production we have ever observed. The "lesser" superheavy elements if you will, would have long ago decayed. Nothing new under the earth.

 

[XK]

Nuclear strong force is what holds a nucleus together, attracting protons and neutrons. Electromagnetic force makes the protons in a nucleus repel each other. Strong force is 137 times stronger than the electromagnetic force, but it degrades in strength very quickly as distance increases. Strong force only has much influence over a distance somewhere around the radius of a proton. Electromagnetic force remains quite strong for distances much larger than that. Once you get beyond 137 protons in a nucleus, there is no way for the strong force to counteract the electromagnetic repulsion any longer. So, as far as we know with our current understanding, element 137 is as far as you can go.

 

[sao123]

Originally posted by: XK
Nuclear strong force is what holds a nucleus together, attracting protons and neutrons. Electromagnetic force makes the protons in a nucleus repel each other. Strong force is 137 times stronger than the electromagnetic force, but it degrades in strength very quickly as distance increases. Strong force only has much influence over a distance somewhere around the radius of a proton. Electromagnetic force remains quite strong for distances much larger than that. Once you get beyond 137 protons in a nucleus, there is no way for the strong force to counteract the electromagnetic repulsion any longer. So, as far as we know with our current understanding, element 137 is as far as you can go.

Is this based on the nuclear shell model predicting the radius of a nucleas? How did you come to this conclusion?

 

[XK]

Originally posted by: sao123
Is this based on the nuclear shell model predicting the radius of a nucleas? How did you come to this conclusion?

I didn't come to this conclusion. It's a result of quantum mechanics which has been known for for quite some time. You may be able to find more detailed information if you do a search on "fine structure constant".

 

[XK]

 

[sao123]

I somewhat understand quantum mechanics, have been doing a lot of reading on it. I recently actually asked a question about nuclear stability with respect to nucleon count. Island of stability kind of thing.

No where in my readings did i see such a conclusion mnetioned. possibly a cite source would be an excellent idea.

 

[Mday]

it is possible. but, if you consider atomic weight and stability, you come across some vague boundaries where the inter-nuclear forces, that is to say, quantum mechanics derived conclusions prevents super high atomic weight and nuclear stability. If any heavier elements did exist, it would have 'decomposed' through nuclear expulsion of subatomic particles. And if anything heavier does exist now, it'd be in areas where we cannot explore, such as the various emerging stars and galaxies.

 

[XK]

sao123:

I just did quite a bit of searching, and can not find any reasonably citeable source, just some forum posts on physics boards and such. It is definitely a result you get when try to calculate stability of very large nuclei. There is also apparently a problem where you get an electromagnetic blackhole with more than 137 protons in a nucleus. The electrons in the first level would have to orbit the nucleus faster than the speed of light, which is not allowed by relativity.

I ran into a similar problem when trying to find a site which gave a good explanation for why electricity causes magnetism. Every site just said "it does because it does". After several hours I finally found a site which referenced lorentz contraction of the moving charges due to relativisitc effects.

The best simple explanation I can give is that strong force can only reach its neighboring nucleons, while the electromagnetic repulsion reaches across the entire nucleus. So the protons are pushed away by every other proton, but only attracted by a neutron they are snuggled right up against. Once you get so many protons pushing they overpower the strong force.

I've been doing a lot of research on quantum mechanics lately myself. If I may, I'd like to recommend R. P. Feynman's "QED: The Strange Theory of Light and Matter" as a great book to lay down some foundations, and pretty much any of his other stuff to take it further. Also, some good websites, especially gsu.edu for reference purposes:


http://pdg.web.cern.ch/pdg/particleadventure/frameless/index.html
http://www.colorado.edu/physics/2000/index.pl?Type=TOC
http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html

 

[MrDudeMan]

thanks for the links and info XK

 

[sao123]

See if you can make sense of these.
Fundamental Proof of Static Nuclear Structure
Nuclear Stability Graph 1
Nuclear Stability Graph 2

 

[Gibsons]

Originally posted by: sao123
See if you can make sense of these.
Fundamental Proof of Static Nuclear Structure
Nuclear Stability Graph 1
Nuclear Stability Graph 2

Just regarding that first link

statements like this...

This essay details a comprehensive study of all isotopes, hydrogen to calcium, copper, iron and gold which reveals an engineering proof that can not be refuted.

...peg my BS meter. Add in the obsessive underlining and absence of references and I'm inclined to read no further.

 

[sao123]

That article in the first link was published in a science journal. I'll see if I can track it down again, since thats where i got it in the first place.

 

[silverpig]

Originally posted by: XK
Nuclear strong force is what holds a nucleus together, attracting protons and neutrons. Electromagnetic force makes the protons in a nucleus repel each other. Strong force is 137 times stronger than the electromagnetic force, but it degrades in strength very quickly as distance increases. Strong force only has much influence over a distance somewhere around the radius of a proton. Electromagnetic force remains quite strong for distances much larger than that. Once you get beyond 137 protons in a nucleus, there is no way for the strong force to counteract the electromagnetic repulsion any longer. So, as far as we know with our current understanding, element 137 is as far as you can go.

That's not actually true. The strong force gets stronger with distance. Two quarks very close to each other have almost no force between them at all (asymptotic freedom), and as you pull them apart, the force gets stronger and stronger.

You can't ever have a bare quark because what happens is you increase the potential energy between the two quarks as you pull them apart, and once you have enough potential energy stored, that energy will turn into mass in the form of two quarks which will then bind to the two you are pulling apart, leaving you with two pairs of bound quarks.

 

[Gibsons]

Originally posted by: sao123
That article in the first link was published in a science journal. I'll see if I can track it down again, since thats where i got it in the first place.

With zero references? I googled the authors name and only got links back to that article. Googling "static nuclear structure" got a link to this though Text

 

[f95toli]

There is no way any journal would publish a text like that. It would never even make it past the editors desk, not to mention the peer-review.

 

[unipidity]

It is worth mentioning that whilst heavier-than-iron elements are largely made in novae etc, its a statistical process. So its entirely possible that some atoms of... ermm... Berkelium have been made just about anywhere, though the core of the earth would be a decent enough place to look. Of course they would decay or fiss (a word?????) PDQ. And its possible that the entire core region might be too low temperature and too small to produce a single atom in a day/week/year/eon...

 

[Chode Messiah]

One theory about superheavy/dense elements, is that there are "islands of stability". Within these islands of stability, there are 1-2 elements that remain stable for thousands of years and would be ultra powerful. Current research shows that there might be an island of stability hovering between 113-130. Also, it has been predicted that a synthetic elements #240-242 could be highly stable elements.

 

[BespinReactorShaft]

I thought you were referring to elements with higher material density than what is known today (Osmium).

 

[Tinker5Thinker2]

Also, on the matter of the range of the Strong Force, wouldn't that radius be on a per-proton/neutron basis?

 

[Biftheunderstudy]

Technically speaking, a neutron star is one big atomic nucleus. But in that case it's gravity binding everything together instead of the strong force.

Though nuclear physics isn't my area of expertise, finding stable nuclei in the very high nucleon numbers is kind of the holy grail in that line of research.

Quantum mechanics and the standard model definitely do not tell us much about this regime since I think perturbation approaches and the like break with really high nucleon numbers. Most of our knowledge about this stuff comes from experiments.