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Author Topic: The Periodic Table Of Elements- how many elements are there ?  (Read 6049 times)

Offline neilep

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Dear Element Experts,

This is the Periodic Table Of Elements:




Nice isn't it ?...I think it would make a nice poster !



Some Element questions If I may:


How are elements discovered ?.....
Does one go in search of elements or are they found by accident ?
Does the elements themselves dictate that there must be others ?
Could there be many hundreds more ?
Are some of the elements shown in the table just theoretical  ? or true bona fide elements ?..which brings me back to my earlier question about whether the nature of elements dictate that their must be others !

Thank you for your help...oh....remember it's me who's asking the questions...so ..please keep your answers .....elemental !!..........*groan....sorry !!..it IS saturday night !!*



« Last Edit: 18/08/2007 22:33:30 by neilep »


 

another_someone

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The Periodic Table Of Elements- how many elements are there ?
« Reply #1 on: 18/08/2007 23:44:11 »
Each element has a unique atomic number, and the atomic number is the number of protons in the atom, from 1 proton in hydrogen to 92 protons in uranium.  Thus is it very easy to simply ask whether an element of a particular number exists - theoretically, one could conjecture that there might exist an element with an atomic number of 1732858, or one of atomic number 763, or any other atomic number.

The more complex issue is how long will a particular atom with a certain atomic number will exist, but how long it will survive - this not only depends on the atomic number, but also the number of neutrons, but the neutrons do not contribute to the chemical properties of the atom.  If an atom will disintegrate in a nanosecond, then even though you can theoretically create such an atom, it will not survive long enough for you to do anything with it.
 

Offline neilep

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The Periodic Table Of Elements- how many elements are there ?
« Reply #2 on: 19/08/2007 01:57:33 »
Thank you George. ..so it's very possible there's an abundance of elements still to be found/discovered/created.

Could make the periodic table quite large in the future.

George, when an atom disintegrates, what happens to it's constituent parts ?
 

another_someone

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The Periodic Table Of Elements- how many elements are there ?
« Reply #3 on: 19/08/2007 04:08:09 »
George, when an atom disintegrates, what happens to it's constituent parts ?

It either fissions (i.e. breaks up into two or more smaller atoms, as happens when Uranium fissions), or it emits a particle of radiation (kind of like a fission, but the bits that is kicked out is not enough to be a small atom in its own right, just a single neutron, or other particle).
 

Offline Bored chemist

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The Periodic Table Of Elements- how many elements are there ?
« Reply #4 on: 19/08/2007 15:29:06 »
In principle you might hope to get an element with atomic number 1000 but in practice you will not. You can make the heavy elements by sticking smaller nuclei together. However as the heavy and superheavy elements are not stable the bits don't usually stick together to form a new nucleus- they just break up or bounce off. Once you get much higher than lead (number 82) there are no stable nuclei. Making heavier nuclei gets increasingly difficult because the products are so unstable. It rapidly becomes impossible to say it you formed a new nucleus but it fell apart or you never made it in the first place. The periodic table is pretty much complete. There is some hope of a bunch of heavy nuclei forming that are relatively stable for their mass but they are still theoretical. Even if they did exist it would only add a few new elements.
 

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The Periodic Table Of Elements- how many elements are there ?
« Reply #4 on: 19/08/2007 15:29:06 »

 

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