# Element 18001 reactium

1. Sep 5, 2007

### Longrange

Element 18001 "reactium"

Lets suppose that someone created element 18001 (although it would only last less than 1 microsecond), an alkaline metal. Noting that Cs reacts twice more vigorously than Rb and Rb twice more vigorously than K, would element 18001 be thousands of times more powerful as Cs?

2. Sep 5, 2007

### olgranpappy

Well... does Fr react "twice more vigorously" than Cs?

Why the hell did you skip all the way to 18001 instead of first considering Fr?

3. Sep 5, 2007

### sas3

This reminds me of a book called "Element 120" it is a Sci-Fi story about the development of element 120. There is a short synopsis at the following link.
http://elements.vanderkrogt.net/element120.html

4. Sep 5, 2007

### DaveC426913

I saw an article in a New Scientist mag talking about element 0 - an atom whose nucleus contains only neutrons.

5. Sep 6, 2007

### olgranpappy

like, for example, a neutron...

6. Sep 6, 2007

### Gokul43201

Staff Emeritus
Element 18001 would not be an alkali metal. The nearest one would be element 18353.

Where do you get these numbers from? How are you quantifying vigor of reaction: rate constants for a given reaction under specified conditions, standard reaction enthalpies, the product of these two ... or something else?

How do you quantify powerfulness?

The reactivity within a group increases with the polarizability of the atom. The polarizability of element 18353 would be about 2 orders of magnitude greater than that of Cs.

Last edited: Sep 6, 2007
7. Sep 6, 2007

### Jimmy Snyder

How about a neutron star? Is that an isotope of element 0?

8. Sep 6, 2007

### DaveC426913

What I don't know is how the atom held itself together (even though it likely did so for only a vanishingly brief time). A neutron star is held together by gravity not by nuclear foces, so I don't think technically that's an atom.

[ EDIT ] Ah. Wiki has this to say:

"Zero has been proposed as the atomic number of the theoretical element tetraneutron. It has been shown that a cluster of four neutrons may be stable enough to be considered an atom in their own right. This would create an element with no protons and no charge on its nucleus.

As early as 1926 Professor Andreas von Antropoff coined the term neutronium for a conjectured form of matter made up of neutrons with no protons, which he placed as the chemical element of atomic number zero at the head of his new version of the periodic table. It was subsequently placed as a noble gas in the middle of several spiral representations of the periodic system for classifying the chemical elements. It is at the centre of the Chemical Galaxy (2005)."

Last edited: Sep 6, 2007
9. Sep 6, 2007

### PatPwnt

Neutronium

10. Sep 7, 2007

### arivero

The usual point is Z=137, so the coupling constant becomes greater than unity and series expansion does not work anymore.

All of the nuclear theory is build in some sense around isospin symmetry breaking. Imagine the nuclear table without electric interaction, or with the sommerfeld constant near 0. then the neutron and proton driplines should be symmetric respect to the diagonal Z=N. Simply to move it from 0 (or 1/infinity) to 1/137 causes the huge assymmetry we live with.

11. Sep 7, 2007

### olgranpappy

And why, pray tell, should the "series expansion" begin to "not work anymore" when Z\alpha becomes greater than one?

12. Sep 7, 2007

### arivero

Well, I do not know the reason, but I read about it somewhere. Hope another people can answer :-( . Note that also QCD series expansion is said to fail because its coupling becomes greater than one at low energy.

For QED, it could be counterargued that it does not work anyway for small alpha (or Z/alpha) because there is some analiticity problem in alpha=0 (Dyson told, time ago in a old paper).

13. Sep 7, 2007

### DaveC426913

Query: what is significant about 18001? Or did you pick it at random? Are elements 118 through 18000 uninteresting?

14. Sep 8, 2007

### Gokul43201

Staff Emeritus
It can't have been chosen carefully, because, as pointed out before, element 18001 is not even an alkali metal.

15. Sep 8, 2007

### arivero

Actually it was a big shoot to assume that the orbital filling rules keep going, there is already some changes at the end of the currently known table, aren't they?

16. Sep 8, 2007

### RetardedBastard

Google scholar returned only 24 results for a search on "neutronium." Quite a few of those results were non-scholarly, like star trek, "alternative view", time travel, etc and almost all results were pretty old stuff. So I wonder if the idea of this "neutronium" has much scientific force (pun strongly intended) behind it. Anyone know?

17. Sep 8, 2007

### Norman

try "tetraneutron"

18. Sep 9, 2007

### Gokul43201

Staff Emeritus
I am not aware of this. What are these changes?

19. Sep 10, 2007

### mormonator_rm

well, Arivero is right about that. The series expansion is based on increasing powers of Z\alpha, so if Z\alpha becomes greater than one, then perturbative methods become useless. This produces a "supercritically" bound nucleus that will produce electron-positron pairs spontaneously, gradually reducing Z back down to 137 via protons and electrons in the nucleus fusing into neutrons, while positrons and electrons annihilate in the electron cloud. This effect has also been extended by analogy to QCD and quark color by the late Dr. Gribov.

20. Sep 10, 2007

### arivero

Again from memory, because my notes on atomic theory are buried in the deep shelves , but I think to remember of some orbitall filling tables alerting of some alterations respect to a naive application of level splitting. Perhaps some issue about spin-orbit in atoms with a lot, really a lot of electrons. Remmeber that the only atom you solve exactly during undergraduate is hidrogen, for all the rest... hartree fock.

On the other hand, if the variations are only on the quantum number m, they only appear when a magnetic field is applied. Hmm. Perhaps this is not for the forum of nuclear physics, but atomic. The original poster was not asking for a property of the nucleus, but for a property of the electronic shell.