# Potential size of the Periodic table. **URL:** \ **Category:** Factual Questions\ **Created:** [August 7, 2013, 8:31pm UTC](https://boards.straightdope.com/t/potential-size-of-the-periodic-table/665632 "2013-08-07T20:31:27Z")\ **Posts on this page:** 8\ **Page:** 2
**Author:** ![scerri](https://avatars.discourse-cdn.com/v4/letter/s/76d3ee/32.png) [@scerri](https://boards.straightdope.com/u/scerri)\ **Post date:** [August 8, 2013, 1:35pm UTC](https://boards.straightdope.com/t/potential-size-of-the-periodic-table/665632/21 "2013-08-08T13:35:30Z")
Interesting question. Opinions differ among experts on what looks like a simple question. According to calculations that neglect the finite size of the nucleus, the maximum is atomic number 137. This approach is based on the magnitude of the “fine structure constant” which is 1/137. The more recent and more fundamental approach predicts a value of 172 or even 173 for the maximum atomic number that can be achieved. Please see my article in the July issue of Scientific American, titled, “Cracks in the Periodic Table.” Also see my website, [www.ericscerri.com](http://www.ericscerri.com) for resources and information on the elements and the periodic table. Eric Scerri PhD UCLA Chemistry Department ---
**Author:** ![LawMonkey](https://avatars.discourse-cdn.com/v4/letter/l/d6d6ee/32.png) [@LawMonkey](https://boards.straightdope.com/u/LawMonkey)\ **Post date:** [August 8, 2013, 3:34pm UTC](https://boards.straightdope.com/t/potential-size-of-the-periodic-table/665632/22 "2013-08-08T15:34:32Z")
Ooooh. **scerri** , thanks for the reply and welcome to the Dope! I’m sure I can speak for everyone in saying we’d love to have you stick around–smart, knowledgeable folk are always in demand around here. I think that particular issue slipped between when I was reading SciAm on planes a bunch and when I picked up an electronic subscription. Might pick up a back issue to check it out, though! ETA: On the other hand, maybe it didn’t. I’ll have to go back and read it again. ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [August 8, 2013, 5:10pm UTC](https://boards.straightdope.com/t/potential-size-of-the-periodic-table/665632/23 "2013-08-08T17:10:46Z")
> [@j\_sum1](#): > > Of course one could argue that a neutron star is really one amazingly large collapsed nucleus with gabazillions of subnuclear particles. > Of course you would have a hard time convincing anyone that it was stable. Its atomic number would be in a state of continual change. I used to think this too, but apparently when the Quantum rears its head things get complicated. It is thought that the core of neutron stars consists mostly of a fluid of free neutrons, rather than superheavy nuclei: > **[Nuclear drip line | Neutron stars](https://en.wikipedia.org/wiki/Nuclear_drip_line#Neutron_stars)** > > In neutron stars, neutron heavy nuclei are found as relativistic electrons penetrate the nuclei and produce inverse beta decay, wherein the electron combines with a proton in the nucleus to make a neutron and an electron-neutrino: ---
**Author:** ![pdunderhill](https://avatars.discourse-cdn.com/v4/letter/p/4bbf92/32.png) [@pdunderhill](https://boards.straightdope.com/u/pdunderhill)\ **Post date:** [August 8, 2013, 7:04pm UTC](https://boards.straightdope.com/t/potential-size-of-the-periodic-table/665632/24 "2013-08-08T19:04:15Z")
Originally Posted by j\_sum1 View Post ‘Of course one could argue that a neutron star is really one amazingly large collapsed nucleus with gabazillions of subnuclear particles.’ Now that is a concept to mull over… Scerri, Kudos to you Sir, IQs measured in room temperature, in Kelvin are invaluable. Pity you’ve never thought of politics. This thread reminds me of a school debating society notion of: ‘This house believes their is a finite amount of knowledge that can be gained from the physical universe.’ As I remember someone buggered up the debate by mentioning Og. Thank you all for casting your knowledge into the platonic cave of my ignorance. Peter ---
**Author:** ![pdunderhill](https://avatars.discourse-cdn.com/v4/letter/p/4bbf92/32.png) [@pdunderhill](https://boards.straightdope.com/u/pdunderhill)\ **Post date:** [August 8, 2013, 7:24pm UTC](https://boards.straightdope.com/t/potential-size-of-the-periodic-table/665632/25 "2013-08-08T19:24:46Z")
Missed the edit, Scerri, in broad terms what are the alternative concepts re: Opinions differ among experts on what looks like a simple question. According to calculations that neglect the finite size of the nucleus, the maximum is atomic number 137. This approach is based on the magnitude of the “fine structure constant” which is 1/137.’ Long words and complex ideas appreciated, grist to the mill. Peter ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [August 8, 2013, 8:24pm UTC](https://boards.straightdope.com/t/potential-size-of-the-periodic-table/665632/26 "2013-08-08T20:24:19Z")
> [@dstarfire](#): > > Element 118 is called ununoctium because the folks who decide element names decided to name stuff using the latin for it’s atomic weight. [nitpick] For its atomic number, not weight. Its standard atomic weight is 284. [/np] ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [August 8, 2013, 10:21pm UTC](https://boards.straightdope.com/t/potential-size-of-the-periodic-table/665632/27 "2013-08-08T22:21:35Z")
137 being the limit is flawed for two reasons. First, that’s just a limit on electrons orbiting the nucleus, not the nucleus itself. But we’ve already extended the table well beyond the point where the nuclei die too quickly to get a chance to attach electrons to them. Secondly, though, the calculation which gives an electron’s speed as some multiple of alpha is a non-relativistic one. If you did somehow have a lump of stuff with a charge of +137 (there are ways to accomplish this), the speed of the electrons about it (to the extent such a thing can even be defined at all, which is already pretty murky in quantum mechanics) would be somewhere in the vicinity of 0.8, not 1, and no matter how high you made the central charge, it still wouldn’t be 1. ---
**Author:** ![cochrane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cochrane/32/10441_2.png) [@cochrane](https://boards.straightdope.com/u/cochrane)\ **Post date:** [August 9, 2013, 2:33am UTC](https://boards.straightdope.com/t/potential-size-of-the-periodic-table/665632/28 "2013-08-09T02:33:27Z")
> [@Gagundathar](#): > > As a Trekker of long standing (that is to say that I have been standing a long time and am a bit tired) Sit long and prosper! 😃 [Previous page](https://boards.straightdope.com/t/potential-size-of-the-periodic-table/665632.md?page=1)