# Is the periodic table finite? **URL:** \ **Category:** Factual Questions\ **Created:** [June 9, 2016, 5:38pm UTC](https://boards.straightdope.com/t/is-the-periodic-table-finite/756931 "2016-06-09T17:38:15Z")\ **Posts on this page:** 12\ **Page:** 3
**Author:** ![joema](https://avatars.discourse-cdn.com/v4/letter/j/a9adbd/32.png) [@joema](https://boards.straightdope.com/u/joema)\ **Post date:** [June 10, 2016, 9:09pm UTC](https://boards.straightdope.com/t/is-the-periodic-table-finite/756931/41 "2016-06-10T21:09:46Z")
> [@Blue\_Blistering\_Barnacle](#): > > …I don’t know why we should expect mile-wide orbitals in giant atoms. I think we’d see the opposite. I think the “mile wide” statement was a thought experiment to try and show that quantum behavior cannot really exist. IOW if a nucleus was 1 mile wide, the electron cloud would be around 10,000 miles wide, and everybody knows that large objects moving over long distances have measurable characteristics and behave in a predictable, familiar fashion. Thus if the electrons orbiting a mile-wide nucleus move in continuous trajectories at finite measurable speeds, then they must likewise do so around the actual quantum nucleus. In fact the behavior at the quantum level is totally different and does not follow normal intuition. It is not possible to make a mile-wide nucleus, nor magnify the quantum nucleus and view it with equivalent resolution. From a quantum standpoint, electrons are point particles and have no physical size, or at least no measurable size. Making a zero-size particle a million times bigger would still be zero size. Likewise electron tunneling is considered to work at infinite speed so if you make the tunneling barrier a mile wide and the electron the size of a basketball it would appear to teleport over that distance in zero time. This cannot really happen at the macro level but that seeming implausibility does not mean it doesn’t happen at the quantum level. ---
**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:** [June 11, 2016, 1:48am UTC](https://boards.straightdope.com/t/is-the-periodic-table-finite/756931/42 "2016-06-11T01:48:24Z")
There is no such thing as a “macro level” absolutely distinguishable from the quantum level. Quantum mechanics applies at all levels. It might be very, very difficult to keep an electron in a mile-wide orbital, but it probably actually happens in deep intergalactic space. And while H[sup]+[/sup], i.e., a bare proton, does have interesting chemical properties, it has those properties mostly by virtue of the potential to have electrons in particular configurations in its vicinity. ---
**Author:** ![brossa](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/brossa/32/3040_2.png) [@brossa](https://boards.straightdope.com/u/brossa)\ **Post date:** [June 12, 2016, 3:23pm UTC](https://boards.straightdope.com/t/is-the-periodic-table-finite/756931/43 "2016-06-12T15:23:45Z")
> [@Chronos](#): > > It might be very, very difficult to keep an electron in a mile-wide orbital, but it probably actually happens in deep intergalactic space. Not disagreeing, but wondering why it would be true in deep space. ---
**Author:** ![Blue\_Blistering\_Barnacle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/blue_blistering_barnacle/32/3386_2.png) [@Blue\_Blistering\_Barnacle](https://boards.straightdope.com/u/Blue_Blistering_Barnacle)\ **Post date:** [June 12, 2016, 4:10pm UTC](https://boards.straightdope.com/t/is-the-periodic-table-finite/756931/44 "2016-06-12T16:10:09Z")
> [@brossa](#): > > Not disagreeing, but wondering why it would be true in deep space. Because in VERY empty space it may be possible to have isolated nuclei, with nothing nearby for miles. While it is true in principle that an electron belonging to a nucleus or molecule in your body has the possibility of being detected out at Jupiter’s orbit, the fact is that that electron will feel forces from numerous other nuclei much more strongly than it will feel forces from its parent in your body, and it will effectively be lost. This happens over microscopic distances in solids and liquids and normal gases (the places where we live). But in deep space, perhaps in the “bubbles” between strings of galactic clusters, nuclei may be very isolated. ---
**Author:** ![Blue\_Blistering\_Barnacle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/blue_blistering_barnacle/32/3386_2.png) [@Blue\_Blistering\_Barnacle](https://boards.straightdope.com/u/Blue_Blistering_Barnacle)\ **Post date:** [June 12, 2016, 4:12pm UTC](https://boards.straightdope.com/t/is-the-periodic-table-finite/756931/45 "2016-06-12T16:12:14Z")
> [@joema](#): > > I think the “mile wide” statement was a thought experiment to try and show that quantum behavior cannot really exist. IOW if a nucleus was 1 mile wide, the electron cloud would be around 10,000 miles wide, and everybody knows that large objects moving over long distances have measurable characteristics and behave in a predictable, familiar fashion. Thus if the electrons orbiting a mile-wide nucleus move in continuous trajectories at finite measurable speeds, then they must likewise do so around the actual quantum nucleus. > > In fact the behavior at the quantum level is totally different and does not follow normal intuition. It is not possible to make a mile-wide nucleus, nor magnify the quantum nucleus and view it with equivalent resolution. From a quantum standpoint, electrons are point particles and have no physical size, or at least no measurable size. Making a zero-size particle a million times bigger would still be zero size. > > Likewise electron tunneling is considered to work at infinite speed so if you make the tunneling barrier a mile wide and the electron the size of a basketball it would appear to teleport over that distance in zero time. This cannot really happen at the macro level but that seeming implausibility does not mean it doesn’t happen at the quantum level. I still maintain that giant high Z nuclei would have smaller orbitals, not larger. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [June 12, 2016, 4:17pm UTC](https://boards.straightdope.com/t/is-the-periodic-table-finite/756931/46 "2016-06-12T16:17:50Z")
> [@Blue\_Blistering\_Barnacle](#): > > I still maintain that giant high Z nuclei would have smaller orbitals, not larger. Why? That’s not the trend in the elements that we know. ---
**Author:** ![Blue\_Blistering\_Barnacle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/blue_blistering_barnacle/32/3386_2.png) [@Blue\_Blistering\_Barnacle](https://boards.straightdope.com/u/Blue_Blistering_Barnacle)\ **Post date:** [June 12, 2016, 7:33pm UTC](https://boards.straightdope.com/t/is-the-periodic-table-finite/756931/47 "2016-06-12T19:33:04Z")
Because as Z increases, there is ever more axis to higher level orbitals (s, then p, then d, then presumably others). The periods (rows) become wider and wider. Atoms become smaller as you move to the right in a period. I’m just guessing that somewhere around Z = one million, that increased “tightness” of an individual orbital caused by higher positive charge in the nucleus will more than offset the fluffiness of additional electrons. At any rate, even if we don’t see atoms getting smaller with higher Z, they don’t get a lot larger, either. Even if one imagines a “YUGE” nucleus the size of a basketball, I don’t think current understanding of atoms says that the electrons have to be outside of the nucleus, and I think calculation of the (90%ile) orbits would be comparable to ordinary atoms. ---
**Author:** ![joema](https://avatars.discourse-cdn.com/v4/letter/j/a9adbd/32.png) [@joema](https://boards.straightdope.com/u/joema)\ **Post date:** [June 12, 2016, 11:47pm UTC](https://boards.straightdope.com/t/is-the-periodic-table-finite/756931/48 "2016-06-12T23:47:30Z")
> [@Blue\_Blistering\_Barnacle](#): > > …While it is true in principle that an electron belonging to a nucleus or molecule in your body has the possibility of being detected out at Jupiter’s orbit… I don’t understand this. The probability of finding a bound electron far from the nucleus drops off quickly. This calculator shows the probability of finding a bound electron far away from the nucleus quickly becomes essentially zero: [Hydrogen Ground State Properties](http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/hydrng.html#c1) If you mean there is practically zero but mathematically non-zero expressible probability, this has no practical meaning since math can easily express things which far exceed the material universe. There are only 8x10^184 Planck volumes in the universe and Planck time is 5.3x10^-44 sec, but it is trivial to vastly exceed these and all combinations of space/time values. This means a tiny but non-zero mathematical probability expression has no necessary practical meaning to the discussion at hand: > **[Graham's number](https://en.wikipedia.org/wiki/Graham%27s_number)** > > Graham's number is an immense number that arose as an upper bound on the answer of a problem in the mathematical field of Ramsey theory. It is much larger than many other large numbers such as Skewes's number and Moser's number, both of which are in turn much larger than a googolplex. As with these, it is so large that the observable universe is far too small to contain an ordinary digital representation of Graham's number, assuming that each digit occupies one Planck volume, possibly the smalles... > **[Knuth's up-arrow notation](https://en.wikipedia.org/wiki/Knuth%27s_up-arrow_notation)** > > In mathematics, Knuth's up-arrow notation is a method of notation for very large integers, introduced by Donald Knuth in 1976. > In his 1947 paper, R. L. Goodstein introduced the specific sequence of operations that are now called hyperoperations. Goodstein also suggested the Greek names tetration, pentation, etc., for the extended operations beyond exponentiation. The sequence starts with a unary operation (the successor function with n = 0), and continues with the binary operations of addition (... > **[Pointless Large Number Stuff - PGLN3: Pointless Gigantic List of Numbers P3...](https://sites.google.com/site/pointlesslargenumberstuff/home/l/pgln3)** > > 10^10^10^1,000,000 ~ 10^^10 > Entries: 28 > [@Blue\_Blistering\_Barnacle](#): > > I’m just guessing that somewhere around Z = one million, that increased “tightness” of an individual orbital caused by higher positive charge in the nucleus will more than offset the fluffiness of additional electrons. … Z is the number of protons in the nucleus. How could you have a nucleus with a million protons since the strong force cannot hold together a nucleus with more than about 126 protons? ---
**Author:** ![Blue\_Blistering\_Barnacle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/blue_blistering_barnacle/32/3386_2.png) [@Blue\_Blistering\_Barnacle](https://boards.straightdope.com/u/Blue_Blistering_Barnacle)\ **Post date:** [June 13, 2016, 11:44am UTC](https://boards.straightdope.com/t/is-the-periodic-table-finite/756931/49 "2016-06-13T11:44:02Z")
By ‘hand-waving’ away the nuclear issue to discuss the electron orbital issue. ---
**Author:** ![Walker\_in\_Eternity](https://avatars.discourse-cdn.com/v4/letter/w/46a35a/32.png) [@Walker\_in\_Eternity](https://boards.straightdope.com/u/Walker_in_Eternity)\ **Post date:** [June 14, 2016, 1:17pm UTC](https://boards.straightdope.com/t/is-the-periodic-table-finite/756931/50 "2016-06-14T13:17:45Z")
[This site](http://www.madsci.org/posts/archives/2001-12/1007653355.Ch.r.html) seems to imply there is a maximum size to the nucleus and hence the periodic table, unless nuclei are made of strange matter. IIRC from my undergraduate physics days the liquid drop model or semi empirical mass formula also limits the binding energy of a nucleus, so theoretically this would put an upper limit on the size of the nucleus. ---
**Author:** ![Blue\_Blistering\_Barnacle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/blue_blistering_barnacle/32/3386_2.png) [@Blue\_Blistering\_Barnacle](https://boards.straightdope.com/u/Blue_Blistering_Barnacle)\ **Post date:** [June 14, 2016, 3:06pm UTC](https://boards.straightdope.com/t/is-the-periodic-table-finite/756931/51 "2016-06-14T15:06:55Z")
> [@Walker\_in\_Eternity](#): > > [This site](http://www.madsci.org/posts/archives/2001-12/1007653355.Ch.r.html) seems to imply there is a maximum size to the nucleus and hence the periodic table, unless nuclei are made of strange matter. > > IIRC from my undergraduate physics days the liquid drop model or semi empirical mass formula also limits the binding energy of a nucleus, so theoretically this would put an upper limit on the size of the nucleus. I’m sure there is a maximum nuclear size, and that was pointed out and explained quite well in some of the first posts in this thread. There were also points made about giant electron orbitals as another limiting factor- that’s what I’m disputing. ---
**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:** [June 14, 2016, 3:21pm UTC](https://boards.straightdope.com/t/is-the-periodic-table-finite/756931/52 "2016-06-14T15:21:41Z")
Wiki’s article on the [Extended periodic table](https://en.wikipedia.org/wiki/Extended_periodic_table) Re. drip lines: this is the limit on how unbalanced a nucleus can be in its proton/neutron raitio. If I’m understanding the article correctly, it’s saying that far enough up the table of nuclei the two lines intersect- that is, beyond that a nucleus would be unstable against _both_ beta decay and positron emission. [Previous page](https://boards.straightdope.com/t/is-the-periodic-table-finite/756931.md?page=2)