what it is...

[M.D. Holloway]

3s2 3p6 4d10 5s2 5p6 4f14 5d10 6s2 6p6 5f7 7s2

[M.D. Holloway]

There are currently seven periods in the periodic table of chemical elements, culminating with atomic number 118. If further elements with higher atomic numbers than this were to be discovered, they would be placed in additional periods, laid out (as with the existing periods) to illustrate periodically recurring trends in the properties of the elements concerned. Any additional periods are expected to contain a larger number of elements than the seventh period, as they are calculated to have an additional so-called g-block, containing 18 elements with partially filled g-orbitals in each period. An eight-period table containing this block was suggested by Glenn T. Seaborg in 1969.

No elements in this region have been synthesized or discovered in nature. (Element 122 was claimed to exist naturally in April 2008, but this claim was widely believed to be erroneous.) The first element of the g-block may have atomic number 121, and thus would have the systematic name unbiunium. Elements in this region are likely to be highly unstable with respect to radioactive decay, and have extremely short half lives, although element 126 is hypothesized to be within an island of stability that is resistant to fission but not to alpha decay. It is not clear how many elements beyond the expected island of stability are physically possible.

According to the orbital approximation in quantum mechanical descriptions of atomic structure, the g-block would correspond to elements with partially-filled g-orbitals. However, spin-orbit coupling effects reduce the validity of the orbital approximation substantially for elements of high atomic number.


The island of stability - the possibility of elements with particularly stable "magic numbers" of protons and neutrons. This would allow certain isotopes of some transuranium elements to be far more stable than others; that is, to decay much more slowly (with half-lives of at least minutes or days, compared to fractions of a second; some have even suggested the possibility of half-lives on the order of millions of years.

[M.D. Holloway]

The idea of the island of stability was first proposed by Glenn T. Seaborg. The hypothesis is that the atomic nucleus is built up in "shells" in a manner similar to the electron shells in atoms. In both cases shells are just groups of quantum energy levels that are relatively close to each other. Energy levels from quantum states in two different shells will be separated by a relatively large energy gap. So when the number of neutrons and protons completely fill the energy levels of a given shell in the nucleus, the binding energy per nucleon will reach a local maximum and thus that particular configuration will have a longer lifetime than nearby isotopes that do not have filled shells.

A filled shell would have "magic numbers" of neutrons and protons. One possible magic number of neutrons for spherical nuclei is 184, and some possible matching proton numbers are 114, 120 and 126 – which would mean that the most stable spherical isotopes would be ununquadium-298, unbinilium-304 and unbihexium-310. Of particular note is Ubh-310, which would be "doubly magic" (both its proton number of 126 and neutron number of 184 are thought to be magic) and thus the most likely to have a very long half-life. (The next lighter doubly-magic spherical nucleus is lead-208, the heaviest stable nucleus and most stable heavy metal.) Isotopes of elements in the range between 110 through 114 have been found to decay more slowly than isotopes of nuclei nearby in the periodic table.

However, recent research indicates that large nuclei are deformed, causing magic numbers to shift. Hassium-270 is now believed to be doubly-magic nucleus, with deformed magic numbers 108 and 162. Its half-life may be as high as 23 seconds.

If there is such a thing as the island of stability with atomic numbers in level 8 or above, it is believed by many that they would be able to support their own gravitational field...

[Lazarro]

My first wife had her own gravitational field.

[Z-man]

Wow - the geek is strong in this thread...

-Z-man.

[looneybin]

better watch that unstable island, it might capsize

[ChemMan]

Wow. You got me. What happened to the 4s2 suborbital? Did you miss the nobel gas or are the electrons hopped up for some reason and jumping the bottom levels?

[tabs]

The idea of the island of stability was first proposed by Glenn T. Seaborg.....in 1969


Seaborg proposed the idea after watching Gilligans Island...probably got rhe idea from the proffessor...that guy was amazing with his being able to turn out all that wonderfull technology out of a couple of coconut shells...

[lm6y]

Yeah Tabs, the SOB could build build a radio out of coconuts, and vines, but he couldn't patch the hull in a boat? What's up with that?

[924slover]

Originally Posted by lm6y

Yeah Tabs, the SOB could build build a radio out of coconuts, and vines, but he couldn't patch the hull in a boat? What's up with that?

Gilligan always screwed it all up. i would have decapitated "little buddy" in a week. (no pun intended)

[porsche4life]

I gunna go with Radium... But thats just a knee jerk answer...

[Aurel]

Gosh, it has been a long time...I counted 67 electrons, so I will say Ho. Yeah, a Ho for Lubemaster.

[BRPORSCHE]

Yup that's exactly what I came to Aurel. But still why the absence of 4s2?

[Joeaksa]

Originally Posted by Lazarro

My first wife had her own gravitational field.

All wives have a gravitational field, and we are not sure where it orbits around...