Is there an end to the periodic table? MSU professor explores its limits

June 8, 2018, Michigan State University
Is there an end to the periodic table? Illustration of part of periodic table of elements with four new elements in period 7 called out, with oganesson element specifically highlighted. Credit: Erin O'Donnell, National Superconducting Cyclotron Laboratory, and Andy Sproles, Oak Ridge National Laboratory

As the 150th anniversary of the formulation of the Periodic Table of Chemical Elements looms, a Michigan State University professor probes the table's limits in a recent Nature Physics Perspective.

Next year will mark the 150th anniversary of the formulation of the created by Dmitry Mendeleev. Accordingly, the United Nations proclaimed 2019 as the International Year of the Periodic Table of Chemical Elements (IYPT 2019). At 150 years old, the table is still growing. In 2016, four new elements were added to it: nihonium, moscovium, tennessine, and oganesson. Their atomic numbers—the number of protons in the nucleus that determines their chemical properties and place in the periodic table—are 113, 115, 117, and 118, respectively.

It took a decade and worldwide effort to confirm these last four elements. And now scientists wonder: how far can this table go? Some answers can be found in a recent Nature Physics Perspective by Witek Nazarewicz, Hannah Distinguished Professor of Physics at MSU and chief scientist at the Facility for Rare Isotope Beams.

All elements with more than 104 protons are labeled as "superheavy", and are part of a vast, totally unknown land that scientists are trying to uncover. It is predicted that atoms with up to 172 protons can physically form a nucleus that is bound together by the nuclear force. That force is what prevents its disintegration, but only for a few fractions of a second.

These lab-made nuclei are very unstable, and spontaneously decay soon after they are formed. For the ones heavier than oganesson, this might be so quick that it prevents them from having enough time to attract and capture an electron to form an atom. They will spend their entire lifetime as congregations of protons and neutrons.

If that is the case, this would challenge the way scientists today define and understand "atoms". They can no longer be described as a central nucleus with electrons orbiting it much like planets orbit the sun.

And as to whether these nuclei can form at all, it is still a mystery.

Scientists are slowly but surely crawling into that region, synthesizing element by element, not knowing what they will look like, or where the end is going to be. The search for element 119 continues at several labs, mainly at the Joint Institute for Nuclear Research in Russia, at GSI in Germany, and RIKEN in Japan.

"Nuclear theory lacks the ability to reliably predict the optimal conditions needed to synthesize them, so you have to make guesses and run fusion experiments until you find something. In this way, you could run for years," said Nazarewicz.

Although the new Facility for Rare Isotope Beams at MSU is not going to produce these superheavy systems, at least within its current design, it might shed light on what reactions could be used, pushing the boundaries of current experimental methods. If element 119 is confirmed, it will add an eighth period to the periodic table. This was captured by the Elemental haiku by Mary Soon Lee: Will the curtain rise?/ Will you open the eighth act?/ Claim the center stage?

Nazarewicz said the discovery might not be too far off: "Soon. Could be now, or in two to three years. We don't know. Experiments are ongoing."

Another exciting question remains. Can superheavy nuclei be produced in space? It is thought that these can be made in neutron star mergers, a stellar collision so powerful that it literally shakes the very fabric of the universe. In stellar environments like this where neutrons are abundant, a nucleus can fuse with more and more neutrons to form a heavier isotope. It would have the same proton number, and therefore is the same , but heavier. The challenge here is that heavy nuclei are so unstable that they break down long before adding more neutrons and forming these superheavy nuclei. This hinders their production in stars. The hope is that through advanced simulations, scientists will be able to "see" these elusive nuclei through the observed patterns of the synthesized elements.

As experimental capabilities progress, scientists will pursue these heavier elements to add to the remodeled table. In the meantime, they can only wonder what fascinating applications these exotic systems will have.

"We don't know what they look like, and that's the challenge", said Nazarewicz. "But what we have learned so far could possibly mean the end of the periodic table as we know it."

MSU is establishing FRIB as a new scientific user facility for the Office of Nuclear Physics in the U.S. Department of Energy Office of Science. Under construction on campus and operated by MSU, FRIB will enable scientists to make discoveries about the properties of rare isotopes in order to better understand the physics of , nuclear astrophysics, fundamental interactions, and applications for society, including in medicine, homeland security and industry.

Explore further: Unresolved puzzles in exotic nuclei

More information: Witold Nazarewicz, The limits of nuclear mass and charge, Nature Physics (2018). DOI: 10.1038/s41567-018-0163-3

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1.8 / 5 (5) Jun 08, 2018
Curious about the total number of elements in our universe? 280, but I won't help with discovering them ;-) Here the original claim of that number, paragraph 56 onwards: http://www.future...port_127
3.7 / 5 (3) Jun 08, 2018
So what about this?

"Long-standing theoretical predictions suggest that also in superheavy elements, filled proton and neutron shells will give rise to extraordinarily stable and hence long-lived nuclei: the "Island of stability". Still, after decades of research, its exact location on the chart of nuclei is a topic of intense discussions and no consensus has yet been reached. While some theoretical models predict a magic proton number to be at element 114, others prefer element 120 or even 126."
5 / 5 (2) Jun 08, 2018
"... with electrons orbiting it much like planets orbit the sun."

That level of abstraction will never demonstrate the limits of the Standard Model's Periodic Table.
1 / 5 (1) Jun 08, 2018
Back in 1990, I built a pyramid of chemical elements that reached to chemical element 140. I could have went far beyond that but stopped at 140. Chemical element 140 contains every atom below 140 and has the same number of protons, electrons, and neutrons as each element is supposed to have. However, each element does not have electrons orbiting around the neculas. Instead, they are in layers stacked on on top of another forming the mysterious pyramid in a solid structure. See my model on my website at or in my free book on my Google Profile, "The Seed of the Universe".
2 / 5 (4) Jun 08, 2018
There are a total of 280 elements. The first poster is correct.
Jun 08, 2018
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5 / 5 (2) Jun 09, 2018
One of the prime difficulties of creating new elements is that the ratio of neutrons to protons tends to increase for the most long lived isotopes. That is true starting at elements a lot lighter than Uranium.

The consequence of this is that the elemental isotopes produced by smashing together lighter elements are intrinsically neutron poor compared with what would be the most stable superheavy isotopes and are therefore among the faster decaying representatives of that element.

And the issue keeps getting worse the heavier the element being produced is.
not rated yet Jun 09, 2018
Anyone else here ever read NOVA by Samuel Delany?
not rated yet Jun 10, 2018
One would think, somewhat like planet size/mass defines (relatively arbitrarily) whether the stellar body is a planet or an asteroid, a halflife of a blob of protons and neutrons should exist long enough to be called a nucleus of an atom.
What is the shortest acceptable half life, you think? A 1 nanosecond perhaps, maybe a little less? I will not go for a picosecond, because no equipment can or likely ever will be able to register it.

There should be some duds on the way to 280.
not rated yet Jun 10, 2018
there is no analogy or comparison among massive bodies and subatomic particles. Planck Time is the minimum time, again hardly comparable to a picosecond.

IIRC Admiral Grace Hopper carried nanoseconds of wire around to illustrate the incommsurability with Planck Seconds.
1 / 5 (1) Jun 11, 2018
Around the world, metal balls have been found that have strange properties. One found near Jacksonville, Florida had taken to following the familiy around like a pet....and it was a metallic object albeit a bit on the heavy side.

They took it to a Navy base to get one of their people to look at it. Supposedly the Navy investigators found that there were smaller objects inside that had the atomic number 140, a superheavy element that we have yet not found.......and it was stable as anything. The government promptly took the object and did not give it back, saying it was probably dangerous. Nothing has been said about it so assume it is VERY classified.

#Parsec mentioned the better stability of neutron rich elements. Perhaps the neutrons need to be there in right ratio to increase 'quark stability'. Nuclear 'particles' contain quarks, and all quarks are made of preons with fractional charges. Perhaps 2 B a tru element, u need all of these in rite ratio.
1 / 5 (1) Jun 11, 2018
To find our true patrimony in our solar system, we need to mine the asteroids where heavy elements from the primordial formation would be available in their more easily accessible centers of mass.
2 / 5 (4) Jun 12, 2018
Around the world, metal balls have been found that have strange properties. One found near Jacksonville, Florida had taken to following the familiy around like a pet....and it was a metallic object albeit a bit on the heavy side.

They took it to a Navy base to get one of their people to look at it. Supposedly the Navy investigators found ...

How far inland 'near Jacksonville, Florida' are we talking here?

Naval Officer, "Could you explain to me one more time, why did you bring a Roomba to a Naval Facility and what are we supposed to do with it?"
1 / 5 (1) Jun 14, 2018
if a neutron is a proton and an electron; then, they occupy the same center or near; note, the amplitude and frequency of any oscillation is undefined. Vpp ~ 0; therefore, freq=?
With this info we build atoms, a set of N pairs within a vol; orbiters of type, and number. I would organized the table as N pairs, from 0 to infinity; a single charge is not a pair, ions; so it depends upon how contained; or simply stability; degrees of freedom; NxN matrix, steady state, or oscillatory. a neutrino is a spherical field update created ate separation. Basics! Definable.
1 / 5 (1) Jun 14, 2018
Might tell Wolfram that electrons are in the nucleus and ask for a charge object with necessary and sufficient attributes to define any matter; or better yet, make it a child's toy that will converged to atoms, compounds, molecules, whatever is placed upon the screen
not rated yet Jun 14, 2018
we need to mine the asteroids where heavy elements from the primordial formation
How about right here? I just watched vid of guys mining platinum from road dust

6g/ton is pretty rich ore. New industry for musk?

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