The Extended Periodic Table Of The Elements
JERIES A. RIHANI

Superactinide Series

"It is probable, in a formal sense at least, that element 122 will begin another series of elements in which each successive electron is added to a deep inner orbital, in a manner similar [see periodic table] to that found in the lanthanide and actinide series. Such a series, which would be listed in a row below the actinide series in the periodic table, should consist of 32 elements, ending in the neighbourhood of element 153 and resulting primarily from the filling of the 5g and 6f inner electron shells.

"Not every element of this new series would correspond to an actinide (or lanthanide) element on a one-to-one basis, and prediction of the chemistry of the members of the series is a complex problem. The difficulty arises partly because of uncertainty of the exact point at which the energetically similar 5g and 6f orbitals begin to fill and partly because calculations indicate that the 8p and 7d orbitals may be very close in energy to the 5g and 6f orbitals. These orbitals may all be filled, then, in a commingling fashion, resulting in a series of elements that show multiple, barely distinguishable oxidation states. The electronic basis for the periodicity shown in the [periodic table] would then no longer be present.

"As shown, element 153 will be the last member of the super-actinide series, at least in a formal sense. The prediction of properties on the basis of an orderly extrapolation appears to be of doubtful validity, however, in this heavy-element region of the periodic table. In still higher-numbered elements, the closely spaced energy levels are expected to make multiple oxidation states the rule. The placement of the elements in the heaviest portion of the periodic table as shown in the [periodic table] is, therefore, probably also of only formal significance." Transuranium Elements, Encyclopaedia Britannica, 1999-2000, (Britannica.com).
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End Of The Periodic Table !

"At some point the stability of the orbital electrons in the ordinary sense must be destroyed as more protons are added to the nucleus. There is, therefore, a critical atomic number, or range of atomic numbers, which represents the end of the periodic table. This end, it should be noted, is separate, at least philosophically, from the question of stability of the nucleus itself; i.e., nuclear stability is not the same as stability of the electron shells. The maximum atomic number, according to current theories, lies somewhere between 170 and 210. However, in a practical sense, the end of the periodic table will come much earlier than this because of nuclear instability (perhaps at or before Z = 120)." Transuranium Elements, Encyclopaedia Britannica, 1999-2000, (Britannica.com). _______________________________________________________

Stability Of Atomic Nucleus

".. why doesn't the concentration of positive electric charge in the nucleus of an atom blow the nucleus apart? Because there is an even stronger force, the strong nuclear force, which overwhelms the electric repulsion on the scale of an atomic nucleus, and holds the nucleons (both protons and neutrons feel the strong force) together. This force does not obey an inverse square law. The force which acts to hold neutrons and protons together in nuclei is actually a vestige of a deeper force, operating within nucleons. This is the true strong interaction, which actually operates directly between quarks, through the exchange of gluons. It has a limited range because gluons have mass (unlike the photons which carry the electromagnetic force, or the gravitons which carry gravity). The range of force carriers like gluons is inversely proportional to their mass, so the more mass they have, the shorter is their range. The force leaks out of individual nucleons to influence the particles next door, but cannot reach outside the nucleus (in a roughly similar way, the overall electric charge on a proton or a neutron is actually the sum of the charges on its constituent quarks; but in that case, provided there is an overall charge, its influence tails off only as the inverse square of distance). The strong force is about 100 times stronger than the electromagnetic force, and as you might expect from this the heaviest stable nuclei have just under 100 protons in each nucleus (plutonium has 94). Add any more, and the overall electrical repulsion (which does add up if all the charges are the same) will overwhelm the strong force, which only operates between next-door nucleons." John Gribbon, Q is for QUANTUM, An Encyclopedia of Particle Physics, first edition, page 143, THE FREE PRESS, Simon & Shuster Inc., 1998 _______________________________________________________

An Island Of Stability

"In January [1999] a team of Russian and American physicists at the Joint Institute for Nuclear Research at Dubna, Russia, announced the creation of element 114. The physicists were able to produce just a single atom of the new element, an isotope containing 114 protons and 184 neutrons in its nucleus. Element 114 lasted an unprecedented 'stable' 30 seconds, long enough to enable its detection, before breaking down (decaying) into lighter elements. Until this discovery, 'superheavy' elements found had been unstable, with lifetimes measured in fractions of a second. For example, element 112, the last element discovered, has a life of just 280 milliseconds. The heavier the element, it seemed, the shorter its life.

"But for the last 30 years, theorists had predicted the existence of 'an island of stability' occurring among the heavier elements - a group of stable elements living long enough to allow for studies of their nuclear behavior and chemistry. The significance of element 114 is its confirmation that scientists have finally landed upon the shores of the 'island of stability' they had only hypothesized about." Donal O'Leary, http://www.infoplease.com/ipa/A0779259.html _______________________________________________________

Electron Configuration Of Element 117

"It is important to realize that the concept of an electronic configuration is an approximate one. It can neither be theoretically predicted with certainty nor can it be experimentally observed. This is quite apart from the fact that samples of 117 and elements like it are so unstable. Indirect evidence for the electronic configuration could in principle be provided by the spectrum of the element. I am not aware of spectral observations on any elements beyond about Z = 100. I would be interested to hear if this has been done and in which cases. Of course we can make educated guesses for configurations of very heavy atoms, guided by the periodic table, but that's all they are, guesses. There is also the complicating factor of relativistic effects in very heavy atoms due to very rapidly moving inner electrons. Relativistic quantum mechanical calculations have provided some predictions but again we cannot confirm them yet. So the next time you see a detailed configuration of any element beyond about 105 bear in mind that this is somewhat hypothetical." Dr. Eric Scerri, UCLA, Chemistry Department, (Message 397, dated 10/28/2000, The Periodic Table Yahoo! Club). _______________________________________________________

Results Of Element 118 Experiment Retracted !

"The team of Berkeley Lab scientists that announced two years ago the observation of what appeared to be Element 118 -- heaviest undiscovered transuranic element at the time -- has retracted its original paper after several confirmation experiments failed to reproduce the results." Berkeley Lab, CA, July 27,2001. _______________________________________________________

V. Rydnik in his book ABC OF QUANTUM MECHANICS is certain the last number in our list of building atoms is 120. "This means that the nuclei (and the atoms as well, naturally) cannot, under any circumstances, have more than about 120 protons." V. Rydnik, ABC OF QUANTUM MECHANICS, translated from the Russian by George Yankovsky, 3rd printing, pages 203-204, Mir Publishers, 1978.

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