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The INTERNET Database of Periodic Tables

There are thousands of periodic tables in web space, but this is the only comprehensive database of periodic tables & periodic system formulations. If you know of an interesting periodic table that is missing, please contact the database curator: Mark R. Leach Ph.D.

Use the drop menus below to search & select from the more than 1300 Period Tables in the database: 

  Text Search:       

Periodic Tables since 2020, by date:

2020   Nuclear Periodic Table
2020   Gierałtowski's Periodic Rotation Table
2020   Nawa Version of Maeno's Nuclear Periodic Table
2020   Vernon's Periodic Table showing the Idealized Solid-State Electron Configurations of the Elements
2020   Correlation of Electron Affinity (F) with Elemental Orbital Radii (rorb)
2020   Vernon's Constellation of Electronegativity
2020   Jodogne's Periodic Table of The Elements
2020   artlebedev's 100,000 Permutation Periodic Table of The Elements
2020   Periodic Ziggurat of The Elements
2020   Scerri's Periodic Table of Books About The Periodic Table & The Chemical Elements
2020   Scerri's Periodic Table of Books About The Periodic Table & The Chemical Elements by ERS
2020   Spiral Electron Spin Periodic Table
2020   Lehikoinen's Circular Clock Form
2020   Vernon's Periodic Treehouse
2020   Workshop on Teaching 3d-4s Orbitals Presented by Dr. Eric Scerri
2020   Vernon's (Partially Disordered) 15 Column Periodic Table
2020   Shukarev's Periodic System (redrawn by Vernon)
2020   Allahyari & Oganov: Mendeleev Numbers & Organising Chemical Space
2020   Zig-Zag Line, Periodic Table
2020   16 Dividing Lines Within The Periodic Table
2020   Split s-, p- & d-Block Periodic Table
2020   Rainbow Periodic Table in ADOMAH Cube
2021   Understanding Periodic and Non-periodic Chemistry in Periodic Tables
2021   Crustal Abundance vs. Electronegativity
2021   van Spronsen's Periodic Table: Update
2021   Helix vs. Screw
2021   Aufbau Periodic Table
2021   Provisional Report on Discussions on Group 3 of The Periodic Table
2021   Nawa's Multi Periodic Table
2021   Vernon's CSF Left-Step Periodic Table
2021   Cubical-Stair Periodic Table
2021   Vernon's Eight-Fold Way Periodic Table
2021   Term & Spin State Periodic Table
2021   Mendeleyev Revisited
2021   History [of the] Elements and Periodic Table
2021   Mendeleyev-Sommerfeld IUPAC Periodic Table
2021   Discoid Periodic Table of The Elements
2021   Rolled-up Version of Benfey's Periodic System
2021   Quantum Periodic Table
2021   Hutcheon Right Step Periodic Table
2021   The Periodic Table: Is it Perfect, is it Fractured or is it Broken?
2022   Hutcheon's Animated Formulation(s) of The Periodic Table
2022   Kudan's Left-Step Periodic Table
2022   Kudan's Left-Step Periodic Table (Short Form)
2022   Kaleidocycle of the Periodic Table
2022   Kudan's Periodic Law (Helix Form)
2022   Which Element is the Best?
2022   Tassitus' Periodic Table
2022   Makeyev's Relativity Matrix of the Elements of Matter (MOEM)
2022   Vernon's Yin Yang of The Periodic Table
2022   Gorodkov's Periodic System of Periodic Systems
2022   99 Elements Sorted by Density & Electronegativity
2022   Tutti Frutti Periodic Table
2022   Deming's 1923 Periodic Table, Updated by Vernon
2022   777 Periodic Wedding Cake
2022   Periodic Table of Periodic Tables
2022   Ramsay-Sommerfeld Periodic Table
2023   DALL-E Pop Art Periodic Table
2023   Mendeleyev’s Periodic Table after Ramsay & Sommerfeld
2023   Marks' Version of Mendeleyev's 1869 Formulation
2023   Element Names: The Etymology of The Periodic Table
2023   Kudan's Periodic System
2023   Six Stages of The Convergence of The Periodic System
2023   Semicircular Hybrid Chart of the Nuclides
2023   Holistic View of Metals & Nonmetals: Exploded View
2023   Chemdex: Valence & Oxidation Number Trends
2024   Kudan's 3D Model of The Periodic Table
2024   Bilateral Symmetry in the Periodic Binodic Table
2024   Marks' Aufspaltung Formulation
2024   Cylindrical Periodic Table with Seven Vertical Columns

Year:  2020 PT id = 1110

Nuclear Periodic Table

A nuclear periodic table by Kouichi Hagino & Yoshiteru Maeno from Kyoto University published in Foundations of Chemistry here & here (open access).

"Elements with proton magic-number nuclei are arranged on the right-most column, just like the noble-gas elements in the familiar atomic periodic table.

"The periodic properties of the nuclei, such as their stability and deformation from spherical shape, are illustrated in the table. Interestingly, there is a fortuitous resemblance in the alignments of the elements: a set of the elements with the magic number nuclei 50(Sn), 82(Pb) and Fl(114) also appears as the group 14 elements in the atomic periodic table. Thanks to this coincidence, there are similarities in the alignments beyond 41(Nb) (e.g., Nb-Ta-Db or La-Ac in the same columns) in both the nuclear and atomic periodic tables of the elements.

"Related documents can be found:

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Year:  2020 PT id = 1111

Gierałtowski's Periodic Rotation Table

Sent by Tomasz Gierałtowski from Poland. There is no information, but Tomasz has provided construction diagrams for each period. Click the links to see these:

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Year:  2020 PT id = 1113

Nawa Version of Maeno's Nuclear Periodic Table

Nagayasu Nawa - "A Japanese school teacher and periodic table designer" - has developed two versons of the Hagino-Maeno Nuclear Periodic Table.

Nawa writes:

"I have made two Nuclear PTs based on Hagino-Maeno (2020). I have tried to express the Nuclear PT visually by using symbols such as '〇','◇','☓' or small '〇' or '●' in a binary way so that people with colour blindness could understand it. And the other have been with the ' QUAD electronic data."

Click either of the images below to enlarge:

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Year:  2020 PT id = 1114

Vernon's Periodic Table showing the Idealized Solid-State Electron Configurations of the Elements

René Vernon writes:

"I've attached a periodic table showing the solid-state electron configurations of the elements. Among other things, it provides a first order explanation as to why elements such as Ln (etc.) like the +3 oxidation state.

"The table includes two versions of the f-block, the first starting with La-Ac; the second with Ce-Th. The table with the first f-block version has 24 anomalies [with respect to Madelung's rule]; the table with the second f-block version has 10 anomalies.

"In the case of the Sc-Y-La-Ac form, I wonder if such a solid-state table is more relevant these days than a table based on gas phase configurations, which has about 20 anomalous configurations.

"Partly we use gas phase configurations since, as Eric Scerri mentioned to me elsewhere, configurations were first obtained (~100 years ago?) from spectroscopy, and this field primarily deals with gas phase atoms. That said, are gas phase configurations still so relevant these days – for this purpose – given the importance of solid-state physics?

"I've never been able to find a periodic table of solid-state electron configurations. Perhaps that has something to do with it? Then again, surely I'm not the first person to have drawn one of these?"

Click image below to enlarge:

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Year:  2020 PT id = 1117

Correlation of Electron Affinity (F) with Elemental Orbital Radii (rorb)

From Jour. Fac. Sci., Hokkaido Univ., Ser. IV. vol. 22, no. 2, Aug., 1987, pp. 357-385, The Connection Between the Properties of Elements and Compounds; Mineralogical-Crystallochemical Classification of Elements by Alexander A. Godovikov & Yu Hariya and expanded by René Vernon who writes.

René Vernon writes:

I was delighted to read about two properties that account for nearly everything seen in the periodic table.

Two properties
While researching double periodicity, I happened upon an obscure article, which simply correlates electron affinity with orbital radius, and in so doing reproduces the broad contours of the periodic table. Having never thought much about the value or significance of EA, and its absence of easily discernible trends, I was suitably astonished. The authors left out the Ln and An and stopped at Bi. They were sitting on a gold mine but provided no further analysis.

I added the data up to Lr, updated the EA values, and have redrawn their graph. It is a thing of beauty and wonderment in its simplest sufficient complexity and its return on investment. I've appended 39 observations, covering all 103 elements.


So there it is, just two properties account for nearly everything.

Click images below to enlarge:

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Year:  2020 PT id = 1122

Vernon's Constellation of Electronegativity

René Vernon has created a "Constellation of Electronegativity" by plotting Electronegativity against Elemental Orbital Radii (rorb)

Observations on the EN plot:

    1. The results are similar to the orbital radii x EA plot, although not quite as clear, including being more crowded
    2. Very good correspondence with natural categories
    3. Largely linear trends seen along groups 1-2, 17 and 15-18 (Ne-Rn)
    4. First row anomaly seen for He (or maybe not since it lines up with the rest of group 2)
    5. For group 13, the whole group is anomalous
    6. For group 14 , the whole group is anomalous no doubt due to the scandide contraction impacting Ge and the double whammy of the lanthanide and 5d contraction impacting Pb
    7. F and O are the most corrosive of the corrosive nonmetals
    8. The rest of the corrosive nonmetals (Cl, Br and I) are nicely aligned with F
    9. The intermediate nonmetals (IM) occupy a trapezium
    10. Iodine almost falls into the IM trapezium
    11. The metalloids occupy a diamond, along with Hg; Po is just inside; At a little outside
    12. Rn is metallic enough to show cationic behaviour and falls into the metalloid diamond
    13. Pd is located among the nonmetals
    14. The proximity of H to Pd is again (coincidentally?) curious given the latter's capacity to adsorb the former
    15. The post-transition metals occupy a narrow strip overlapping the base of the refractory metal parallelogram
    16. Curiously, Zn, Cd, and Hg (a bit stand-off-ish) are collocated with Be, and relatively distant from the PTM and the TM proper
    17. The ostensibly noble metals occupy an oval; curiously, W is found here; Ag is anomalous given its greater reactivity; Cu, as a coinage metal, is a little further away
    18. Au and Pt are nearest to the halogen line
    19. The ferromagnetic metals (Fe-Co-Ni) are colocated
    20. The refractory metals, Nb, Ta, Mo, W and Re are in a parallelogram, along with Cr and V; Tc is included here too
    21. Indium is the central element of the periodic table in terms of mean orbital radius and EN; Tc is next as per the EA chart
    22. The reversal of He compared to the rest of the NG reflects #24
    23. All of the Ln and An fall into an oval of basicity, bar Lr
    24. The reversal of the positions of Fr and Cs is consistent with Cs being the most electronegative metal
    25. A similar, weaker pattern is seen with Ba and Ra. 

Click to enlarge:

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Year:  2020 PT id = 1131

Jodogne's Periodic Table of The Elements

Dr.Ir.Jodogne Jean Claude writes:

"I have the pleasure to send to you my paper on the PT which appears in Chimie Nouvelle 133 of the Soc.Royale de Chimie. However for the moment it is in French. The paper contains and explains the ultimate evolution of my preceding PT but it is the most scientifically based. Pedagogically, I believe it is interesting and easy. As you will see it keeps most of the chemical usual properties of the traditional one."

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Year:  2020 PT id = 1132

artlebedev's 100,000 Permutation Periodic Table of The Elements

Moscow-based design company Art. Lebedev Studio have released a new Periodic Table which can be adapted for any task.

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Year:  2020 PT id = 1147

Periodic Ziggurat of The Elements

By René Vernon, the Periodic Ziggurat of the Elements. Click to enlarge:

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Year:  2020 PT id = 1149

Scerri's Periodic Table of Books About The Periodic Table & The Chemical Elements

From Eric Scerri, a periodic table of books about the periodic table & the chemical elements... many by Eric Scerri himself.

Eric Scerri, UCLA, Department of Chemistry & Biochemistry. See the website and Eric's Twitter Feed.

Click to enlarge:

There is no particular connection between each of the elements and the book associated with it in the table, with the exception of: H, He, N, Ti, V, Nb, Ag, La, Au, Ac, U, Pu & Og.

The following is a list of references for each of the 118 books featured on Periodic Table of Books About The Periodic Table & The Chemical Elements. Books published in languages other than English are shown in color. They include the Catalan, Croatian, French, German, Italian, Norwegian & Spanish languages:

1 H J. Ridgen, Hydrogen, the Essential Element, Harvard University Press, Cambridge, MA, 2002.
2 He W.M. Sears Jr., Helium, The Disappearing Element, Springer, Berlin, 2015.
3 Li K. Lew, The Alkali Metals, Rosen Central, New York, 2009.
4 Be S. Esteban Santos, La Historia del Sistema Periodico, Universidad Nacional de Educación a Distancia, Madrid, 2009. (Spanish)
5 B E.R. Scerri. The Periodic Table, Its Story and Its Significance, 2nd edition, Oxford University Press, New York, 2020.
6 C U. Lagerkvist, The Periodic Table and a Missed Nobel Prize, World Scientific, Singapore, 2012.
7 N W.B. Jensen, Mendeleev on the Periodic Law: Selected Writings, 1869–1905, Dover, Mineola, NY, 2005.
8 O M. Kaji, H. Kragh, G. Pallo, (eds.), Early Responses to the Periodic System, Oxford University, Press, New York, 2015.
9 F E. Mazurs, Graphic Representation of the Periodic System During One Hundred Years, Alabama University Press, Tuscaloosa, AL, 1974.
10 Ne T. Gray, The Elements: A Visual Exploration of Every Known Atom in the Universe, Black Dog & Leventhal, 2009.
11 Na N.C. Norman, Periodicity and the s- and p-Block Elements, Oxford University Press, Oxford, 2007.
12 Mg M. Gordin, A Well-Ordered Thing, Dimitrii Mendeleev and the Shadow of the Periodic Table, 2nd edition, Basic Books, New York, 2019.
13 Al S. Kean, The Disappearing Spoon, Little, Brown & Co., New York, 2010.
14 Si P.A. Cox, The Elements, Oxford University Press, Oxford, 1989.
15 P J. Emsley, The 13th Element: The Sordid Tale of Murder, Fire, and Phosphorus, Wiley, New York, 2002.
16 S P. Parsons, G. Dixon, The Periodic Table: A Field Guide to the Elements, Qurcus, London, 2014.
17 Cl P. Levi, The Periodic Table, Schocken, New York, 1995.
18 Ar B.D. Wiker, The Mystery of the Periodic Table, Bethlehem Books, New York, 2003.
19 K H. Alderesey-Williams, Periodic Tales, Viking Press, 2011.
20 Ca P. Strathern, Mendeleyev's Dream, Hamish-Hamilton, London, 1999.
21 Sc D. Scott, Around the World in 18 Elements, Royal Society of Chemistry, London, 2015.
22 Ti E. W. Collings, Gerhard Welsch, Materials Properties Handbook: Titanium Alloys, ASM International, Geauga County, Ohio, 1994.
23 V D. Rehder, Bioinorganic Vanadium Chemistry, Wiley-Blackwell, Weinheim, 2008.
24 Cr K. Chapman, Superheavy, Bloomsbury Sigma, New York, 2019.
25 Mn E.R. Scerri, E. Ghibaudi (eds.), What is an Element? Oxford University Press, New York, 2020.
26 Fe M. Soon Lee, Elemental Haiku, Ten Speed Press, New York, 2019.
27 Co J. Emsley, Nature's Building Blocks, An A-Z Guide to the Elements, Oxford University Press, Oxford, 2001.
28 Ni T. James, Elemental, Robinson, London, 2018.
29 Cu E.R. Scerri, The Periodic Table, Its Story and Its Significance, Oxford University Press, New York, 2007.
30 Zn H. Rossotti, Diverse Atoms, Oxford University Press, Oxford, 1998.
31 Ga P. Ball, A Very Short Introduction to the Elements, Oxford University Press, 2004.
32 Ge I. Asimov, The Building Blocks of the Universe, Lancer Books, New York, 1966.
33 As J. Browne, Seven Elements that Changed the World, Weidenfeld and Nicholson, London, 2013.
34 Se N. Raos, Bezbroj Lica Periodnog Sustava Elemenata, Technical Museum of Zagreb, Croatia, 2010. (Croatian)
35 Br P. Strathern, The Knowledge, The Periodic Table, Quadrille Publishing, London, 2015.
36 Kr A. Ede, The Chemical Element, Greenwood Press, Westport, CT, 2006.
37 Rb A. Stwertka, The Elements, Oxford University Press, Oxford, 1998.
38 Sr E.R. Scerri, A Tale of Seven Elements, Oxford University Press, New York, 2013.
39 Y H.-J. Quadbeck-Seeger, World of the Elements, Wiley-VCH, Weinheim, 2007.
40 Zr M. Fontani, M. Costa, M.V. Orna (eds.), The Lost Elements, Oxford University Press, New York, 2015.
41 Nb M. Seegers, T. Peeters (eds.), Niobium: Chemical Properties, Applications and Environmental Effects, Nova Science Publishers, New York, 2013.
42 Mo E.R. Scerri, Selected Papers on the Periodic Table, Imperial College Press, Imperial College Press, London and Singapore, 2009.
43 Tc A. Dingle, The Periodic Table, Elements with Style, Kingfisher, Richmond, B.C. Canada, 2007.
44 Ru G. Rudorf, Das periodische System, seine Geschichte und Bedeutung für die chemische Sysytematik, Hamburg-Leipzig, 1904. (German)
45 Rh I. Nechaev, G.W. Jenkins, The Chemical Elements, Tarquin Publications, Publications, Norfolk, UK, 1997.
46 Pd P. Davern, The Periodic Table of Poems, No Starch Press, San Francisco, 2020.
47 Ag C. Fenau, Non-ferrous metals from Ag to Zn, Unicore, Brussells, 2002.
48 Cd J. Van Spronsen, The Periodic System of the Chemical Elements, A History of the First Hundred Years, Elsevier, Amsterdam, 1969.
49 In M. Tweed, Essential Elements, Walker and Company, New York, 2003.
50 Sn M.E. Weeks, Discovery of the Elements, Journal of Chemical Education, Easton PA, 1960.
51 Sb P. Wothers, Antimony Gold Jupiter's Wolf, Oxford University Press, Oxford, 2019.
52 Te W. Zhu, Chemical Elements in Life, World Scientific Press, Singapore, 2020.
53 I O. Sacks, Uncle Tungsten, Vintage Books, New York, 2001.
54 Xe E.R. Scerri, (ed.), 30-Second Elements, Icon Books, London, 2013.
55 Cs M. Jacob (ed.), It's Elemental: The Periodic Table, Celebrating 80th Anniversary, Chemical & Engineering News, American Chemical Society, Washington D.C., 2003.
56 Ba J. Marshall, Discovery of the Elements, Pearson Custom Publishing, New York,1998.
57 La K. Veronense, Rare, Prometheus Books, Amherst, New York, 2015.
58 Ce N. Holt, The Periodic Table of Football, Ebury Publishing, London, 2016.
59 Pr S. Alvarez, C. Mans, 150 Ans de Taules Périodiques a la Universitat de Barcelona, Edicions de la Universitat de Barcelona, Barcelona, 2019. (Catalan)
60 Nd L. Garzon Ruiperez, De Mendeleiev a Los Superelementos, Universidad de Oviedo, Oviedo, 1988. (Spanish)
61 Pm P. Ball, A Guided Tour of the Ingredients, Oxford University Press, Oxford, 2002.
62 Sm S. Esteban Santos, La Historia del Sistema Periodico, Universidad Nacional de Educación a Distancia, Madrid, 2009. (Spanish).
63 Eu A. E. Garrett, The Periodic Law, D. Appleton & Co., New York, 1909.
64 Gd M.S. Sethi, M. Satake, Periodic Tables and Periodic Properties, Discovery Publishing House, Delhi, India, 1992.
65 Tb M. Eesa, The cosmic history of the elements: A brief journey through the creation of the chemical elements and the history of the periodic table, Createspace Independent Publishing Platform, 2012.
66 Dy P. Depovere, La Classification périodique des éléments, De Boeck, Bruxelles, 2002. (French).
67 Ho F. Habashi, The Periodic Table & Mendeleev, Laval University Press, Quebec, 2017.
68 Er W.J. Nuttall, R. Clarke, B. Glowacki, The Future of Helium as a Natural Resource, Routledge, London, 2014.
69 Tm R.D. Osorio Giraldo, M.V. Alzate Cano, La Tabla Periodica, Bogota, Colombia, 2010. (Spanish).
70 Yb P.R. Polo, El Profeta del Orden Quimico, Mendeleiev, Nivola, Spain, 2008. (Spanish).
71 Lu E.R. Scerri, A Very Short Introduction to the Periodic Table, 2nd edition, Oxford University Press, Oxford, 2019.
72 Hf D.H. Rouvray, R.B. King, The Mathematics of the Periodic Table, Nova Scientific Publishers, New York, 2006.
73 Ta P. Thyssen, A. Ceulemans, Shattered Symmetry, Oxford University Press, New York, 2017.
74 W P.W. Atkins, The Periodic Kingdom, Basic Books, New York, NY, 1995.
75 Re D.G. Cooper, The Periodic Table, 3rd edition. Butterworths, London, 1964.
76 Os E. Lassner, W.-D. Schubert, Tungsten: Properties, Chemistry, Technology of the Element, Alloys, and Chemical Compounds, Springer, Berlin, 1999.
77 Ir J.C.A. Boeyens, D.C. Levendis, Number Theory and the Periodicity of Matter, Springer, Berlin, 2008.
78 Pt R. Hefferlin, Periodic Systems and their Relation to the Systematic Analysis of Molecular Data, Edwin Mellen Press, Lewiston, NY, 1989.
79 Au R.J. Puddephatt, The Chemistry of Gold, Elsevier, Amsterdam, 1978.
80 Hg D.H. Rouvray, R.B. King, The Periodic Table Into the 21st Century, Research Studies Press, Baldock, UK, 2004.
81 Tl R.E. Krebs, The History and Use of Our Earth's Chemical Elements, Greenwood Publishing Group, Santa Barbara, CA, 2006.
82 Pb E. Torgsen, Genier, sjarlataner og 50 bøtter med urin - Historien om det periodiske system, Spartacus, 2018. (Norwegian).
83 Bi K. Buchanan, D. Roller, Memorize the Periodic Table, Memory Worldwide Pty Limited, 2013.
84 Po D. Morris, The Last Sorcerers, The Path from Alchemy to the Periodic Table, Joseph Henry Press, New York, 2003.
85 At T. Jackson, The Elements, Shelter Harbor Press, New York, 2012.
86 Rn R.J.P. Williams, J.J.R. Frausto da Silva, The Natural Selection of the Chemical Elements: The Environment and Life's Chemistry, Clarendon Press, Oxford, 1997.
87 Fr G. Rudorf, The Periodic Classification and the Problem of Chemical Evolution, Whittaker & Co., London, New York, 1900.
88 Ra L. Van Gorp, Elements, Compass Point Books, Manakato, MN, 2008.
89 Ac G.T. Seaborg, J.J. Katz, L.R. Morss, Chemistry of the Actinide Elements, Springer, Berlin, 1986.
90 Th G. Münzenberg, Superheavy Elements - Searching for the End of the Periodic Table, Manipal Universal Press, India, 2018.
91 Pa A. Castillejos Salazar, La Tabla Periòdica: Abecedario de la Quimica, Universidad Autonoma de Mexico, D.F. Mexico, 2005. (Spanish).
92 U T. Zoellner, Uranium, Penguin Books, London, 2009.
93 Np J. Barrett, Atomic Structure and Periodicity, Royal Society of Chemistry, London, 2002.
94 Pu J. Bernstein, Plutonium, Joseph Henry, Washington DC, 2007.
95 Am S. Hofmann, Beyond Uranium, Taylor & Francis, London, 2002.
96 Cm H.M. Davis, The Chemical Elements, Ballantine Books, New York, 1961.
97 Bk P.González Duarte, Les Mils Cares de la Taula Periòdica, Universitat Autonoma de Barcelona, Bellaterra Barcelona, 2005 (Catalan).
98 Cf R. Rich, Periodic Correlations, Benjamin, New York, 1965.
99 Es E. Rabinowitsch, E. Thilo, Periodisches System, Geschichte und Theorie, Stuttgart, 1930. (German).
100 Fm P.K. Kuroda, The Origin of the Chemical Elements, and the Oklo Phenomenon, Springer-Verlag, Berlin, 1982.
101 Md G. Villani, Mendeleev,  La Tavola Periodica Degli Elementi, Grandangolo, Milan, 2016. (Italian).
102 No J. Russell, Elementary: The Periodic Table Explained, Michael O'Mara, London, 2020.
103 Lr P. Enghag, Encyclopedia of the Elements, Wiley-VCH, Weinheim, 2004.
104 Rf R.J. Puddephatt, The Periodic Table of the Elements, Oxford University Press, Oxford, 1972.
105 Db L. Ohrström, The Last Alchemist in Paris, Oxford University Press, New York, 2013.
106 Sg N.N. Greenwood, E. Earnshaw, Chemistry of the Elements, 2nd edition, Elsevier, Amsterdam, 1997.
107 Bh R. Luft, Dictionnaire des Corps Simples de la Chimie, Association Cultures et Techniques, Nantes, 1997. (French)
108 Hs Science Foundation Course Team, The Periodic Table and Chemical Bonding, The Open University, Milton Keynes, 1971.
109 Mt W.W. Schulz, J. Navratil, Transplutonium Elements, American Chemical Society, Washington D.C., 1981.
110 Ds I. Nechaev, Chemical Elements, Lindsay Drummond, 1946.
111 Rg F. Hund, Linienspektren und Periodisches System Der Elemente, Springer, Berlin, 1927.
112 Cn F.P. Venable, The Development of the Periodic Law, Chemical Publishing Co., Easton, PA, 1896.
113 Nh O. Baca Mendoza, Leyes Geneticas de los Elementos Quimicos. Nuevo Sistema Periodico, Universidad Nacional de Cuzco, Cuzco, Peru, 1953 (Spanish).
114 Fl B. Yorifuji, Wonderful Life with the Elements, No Starch Press, San Francisco, 2012.
115 Mc D.I. Mendeléeff, The Principles of Chemistry, American Home Library, New York, 1902.
116 Lv A. Lima-de-Faria, Periodic Tables Unifying Living Organisms at the Molecular Level: The Predictive Power of the Law of Periodicity, World Scientific Press, Singapore, 2018.
117 Ts H.B. Gray, J.D. Simon, W.C. Trogler, Braving the Elements, University Science Books, Sausalito, CA, 1995.
118 Og E.R. Scerri, G. Restrepo, Mendeleev to Oganesson, Oxford University Press, New York, 2018.
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Year:  2020 PT id = 1153

Scerri's Periodic Table of Books About The Periodic Table & The Chemical Elements by ERS

From Eric Scerri, a periodic table of books about the periodic table & the chemical elements... by Eric Scerri, including translations.

Eric Scerri, UCLA, Department of Chemistry & Biochemistry. See the website and Eric's Twitter Feed.

Click to enlarge:

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Year:  2020 PT id = 1154

Spiral Electron Spin Periodic Table

The Spiral Electron Spin Periodic Table, By Justine Colburn, who also developed the Genesis formulation.

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Year:  2020 PT id = 1158

Lehikoinen's Circular Clock Form

Otto Lehikoinen writes:

"A circular form separating 1s orbital to the center, set it on a wall clock as there are 48 elements of main periods, thus can be used as markers for half hours. Group 4 is centered on noon and group 7 starts the afternoon, to get anions and cations with the same but opposite charge to be beside each other. Thus the noble gases are centered on midnight which is easily remembered by neon (and other noble gas) lights. The minute hand hits the 40 d-block elements giving an accuracy of 1.5 minutes and seconds could be read from lanthanides and actinides."

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Year:  2020 PT id = 1161

Vernon's Periodic Treehouse

René Vernon's Periodic Treehouse of the Elements, fearuring the World's longest dividing line between metals and nonmetals.

René writes:

I can't remember what started me off on this one. It may have been Mendeleev's line, as shown on the cover of Bent's 2006 book, New ideas in chemistry from fresh energy for the periodic law.

There are a few things that look somewhat arbitrary, so I may revisit these:

Click to enlarge:

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Year:  2020 PT id = 1162

Workshop on Teaching 3d-4s Orbitals Presented by Dr. Eric Scerri

Dr. Eric Scerri, UCLA Department of Chemistry & Biochemistry, discusses many of the issues concerning the periodic table: the aufbau principle, Madelung's rule, the electronic and anomalous electronic structures of the transition elements, the Sc2+ ion, the Janet Left Step, Group 3: Sc, Y, Lu, Lr vs. Sc, Y, La, Ac, atomic spectroscopy, etc.

Many of the topics that concern those of us interested in the periodic table are discussed.

Thanks to Eric Scerri – who appears – for the tip! 
See the website and Eric's Twitter Feed.

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Year:  2020 PT id = 1165

Vernon's (Partially Disordered) 15 Column Periodic Table

A formulation by René Vernon, who writes:

"Here is a 15-column table which is a hybrid of a Mendeleev 8-column table and an 18-column standard table. The key relocations are the p-block nonmetals to the far left; and the coinage and post-transition metals under their s and early d-block counterparts.

"Taking a leaf out of Mendeleev's playbook, I ignored atomic number order when this seemed appropriate. It's refreshing to see the traditional horizontal gaps between blocks disappear. (DIM did not like these.)

"Since Dias (2004, see references below) reckoned a periodic table is a partially ordered set forming a two-dimensional array, I believe I now have a partially ordered table that is partially disordered twice over.

"The table has some curious relationships. Equally, some relationships seen in the standard form are absent. The Group 2, 3, and aluminium dilemmas disappear. This confirms my impression that such dilemmas have no intrinsic meaning. Rather, their appearance or non-appearance is context dependent."

Notes & references below.

Groups 1 to 4 have either a C or F suffix where C (nonmetal) is after the importance of carbon to our existence; and F (metal) is for the importance of iron to civilisation.

Groups 1C and 1F present the greatest contrast in nonmetallic and metallic behaviour.

Coactive Nonmetals: They are capable of forming septenary heterogeneous compounds such as C20H26N4O10PSSe.

Group 2C: Helium is shaded as a noble gas. "Heliox" is a breathing gas mixture of helium and oxygen used in saturation diving, and as a medical treatment for patients with difficulty breathing.

Group 3C: Boron over nitrogen looks odd. Yet one boron atom and one nitrogen atom have the same number of electrons between them as two adjacent carbon atoms. The combination of nitrogen and boron has some unusual features that are hard to match in any other pair of elements (Niedenzu & Dawson 1965).

Boron and phosphorus form a range of ring and cage compounds having novel structural and electronic properties (Paine et al. 2005).

Metalloids. I treat them here as nonmetals given their chemistry is predominately that of chemically weak nonmetals.

Metals: The labels electropositive; transition; and electronegative are adapted from Kornilov (2008).

Group 1F: Monovalent thallium salts resemble those of silver and the alkali metals.

An alloy of cesium (73.71%), potassium (22.14%) and sodium (4.14%) has a melting point of –78.2°C (–108.76°F) (Oshe 1985).

Silver, copper, and gold, as well as being the coinage metals, are borderline post-transition metals.

Group 2F: Beryllium and magnesium are not in fact alkaline earths. Beryllium is amphoteric rather than alkaline; magnesium was isolated in impure form from its oxides, unlike the true alkaline earths. The old ambiguity over whether beryllium and magnesium should go over calcium or zinc has gone.

Nobelium is here since +2 is its preferred oxidation state, unlike other actinoids.

Group 3F: Aluminium is here in light of its similarity to scandium (Habishi 2010).

InGaAsP is a semiconducting alloy of gallium arsenide and indium phosphide, used in lasers and photonics.

There is no Group 3 "issue" since lanthanum, actinium, lutetium and lawrencium are in the same family.

Gold and aluminium form an interesting set of intermetallic compounds known as Au5Al2 (white plague) and AuAl2 (purple plague). Blue gold is an alloy of gold and either gallium or indium.

Lanthanoids: The oxidation state analogies with the transition metals stop after praseodymium. That is why the rest of lanthanoids are footnoted in dash-dot boxes.

Actinoids: The resemblance to their transition metal analogues falters after uranium, and peters out after plutonium.

Group 4F: It's funny to see titanium—the lightweight super-metal—in the same group as lead, the traditional "heavy" metal.

This is the first group impacted by the lanthanoid contraction (cerium through lutetium) which results in the atomic radius of hafnium being almost the same as that of zirconium. Hence "the twins".

The chemistry of titanium is significantly different from that of zirconium and hafnium (Fernelius 1982).

Lead zirconate titanate Pb[ZrxTi1–x]O3 (0 ≤ x ≤ 1) is one of the most commonly used piezo ceramics.

Group 5: Bismuth vanadate BiVO4 is a bright yellow solid widely used as a visible light photo-catalyst and dye.

Steel Friends: The name is reference to their use in steel alloys. They have isoelectronic soluble oxidizing tetroxoanions, plus a stable +3 oxidation state. (Rayner-Canham 2020).

Ferromagnetic Metals: The horizontal similarities among this triad of elements (as is the case among the PGM hexad) are greater than anywhere in the periodic table except among the lanthanides (Lee 1996). The +2 aqueous ion is a major component of their simple chemistry (Rayner-Canham 2020).

Group 8: "Rubiferous metals" (classical Latin rubēre to be red; -fer producing) is from the reddish-brown colour of rust; the most prevalent ruthenium precursor being ruthenium trichloride, a red solid that is poorly defined chemically but versatile synthetically; and the red osmates [OsO4(OH)4]?2 formed upon reaction by osmium tetroxide with a base.

Group 9: "Weather metals" comes from the use of cobalt chloride as a humidity indicator in weather instruments; rhodium plating used to "protect other more vulnerable metals against weather exposure as well as against concentrated acids or acids fumes" (Küpfer 1954); and the "rainbow" etymology of iridium.

Group 10: "Catalytic metals" is after a passage in Greenwood and Earnshaw, "They are... readily obtained in finely divided forms which are catalytically very active." (2002). Of course, many transition metals have catalytic properties. That said, if you asked me about transition metal catalysts, palladium and platinum would be the first to come to mind. Group 10 appear to be particularly catalytic.


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Year:  2020 PT id = 1168

Shukarev's Periodic System (redrawn by Vernon)

Shukarev SA 1975, "On the image of the periodic system with the use of fifth move of late a-elements", Collection of Scientific and Methodological Articles on Chemistry. M.: Higher School, no 4, pp 3-12 (in Russian). Redrawn and commented upon by René Vernon:

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Year:  2020 PT id = 1169

Allahyari & Oganov: Mendeleev Numbers & Organising Chemical Space

This formulation may not look like a periodic table, but look again.

Zahed Allahyari & Artem R. Oganov, Nonempirical Definition of the Mendeleev Numbers: Organizing the Chemical Space, J. Phys. Chem. C 2020, 124, 43, 23867–23878, A preprint version of the paper is available on the arxiv preprint server.


Organizing a chemical space so that elements with similar properties would take neighboring places in a sequence can help to predict new materials. In this paper, we propose a universal method of generating such a one-dimensional sequence of elements, i.e. at arbitrary pressure, which could be used to create a well-structured chemical space of materials and facilitate the prediction of new materials.

This work clarifies the physical meaning of Mendeleev numbers, which was earlier tabulated by Pettifor. We compare our proposed sequence of elements with alternative sequences formed by different Mendeleev numbers using the data for hardness, magnetization, enthalpy of formation, and atomization energy. For an unbiased evaluation of the MNs, we compare clustering rates obtained with each system of MNs.

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Year:  2020 PT id = 1170

Zig-Zag Line, Periodic Table

Periodic Table showing the (regular) zig-zag line by René Vernon who writes:

"It is curious that the full extent of the line has never been properly mapped (to my knowledge).

"Elements on the downside of the line generally display increasing metallic behaviour; elements on the topside generally display increasing nonmetallic behaviour.

"When you see the line you will usually see only about a quarter of it. The line actually runs all the way across the periodic table, as shown, for a total of 44 element box sides.

"Interpretations vary as to where the line runs. None of these is better than any other of them, provided the interpretation is explained to you. The thick black line (at least in the p-block) is the most common version. The metalloids tend to lie to either side of it.

"Polonium and astatine are shown here as post-transition metals although either or both of them are sometimes shown as metalloids (or, in the case of astatine, as a halogen). Polonium conducts electricity like a metal and forms a cation in aqueous solution. In 2013, astatine was predicted to be a centred cubic-metal Condensed Astatine: Monatomic and Metallic This prediction has been cited 35 times, with no dissenters. Astatine also forms a cation in aqueous solution. Oganesson is shown as having (as yet) unknown properties.

"The dashed lines show some alternative paths for the zigzag line.

"The lower one treats the metalloids as nonmetals since metalloid chemistry is predominately nonmetallic. The lower line and the upper line are sometimes shown together used when the metalloids are treated as neither metals nor nonmetals."

And in Janet Left-Step form:

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Year:  2020 PT id = 1171

16 Dividing Lines Within The Periodic Table

René Vernon points out that there are 16 dividing lines within the periodic table.

A-Z Dividing Lines:

48-crash line: Named after the dramatic reduction in physical metallic character after group 11, Cd being Z = 48. Group 12 show few transition metal attributes and behave predominantly like post-transition metals.

Big bang line: H makes up about 73% of the visible universe.

Corrosive line: O, F, Cl = most corrosive nonmetals.

d-Block fault line: Group 3 show little d-block behaviour; group 4 is the first in which characteristic d-block behaviour occurs.

Deming line: Demarcates the metalloids from the pre-halogen nonmetals. The "reactive" nonmetals to the right of the metalloids each have a sub-metallic appearance (C, O, Se, I).

Edge of the world line: No guesses for this one.

Klemm line: Klemm, in 1929, was the first to note the double periodicity of the lanthanides (Ce to Lu). Lockyer line: After the discoverer of He, the first element not found on Earth.

Ørsted line: After the magnetic effects believed to be responsible for Mn having a crystalline structure analogous to white P; Tc: First radioactive metal; Re: Last of the refractory metals; "most radioactive" of the naturally occurring elements with stable isotopes. Fe: First of the ferromagnetic metals; Ru: First noble metal; Os: Densest of naturally occurring metals. The number of unpaired d electrons peaks in group 7 and reduces thereafter.

Platypus line: Tl shows similarities to Rb, Ag, Hg, Pb.

Poor metal line: Most metals (80%) have a packing factor (PF)3 68%. Ga: Has a crystalline structure analogous to that of iodine. BCN 1+6.* PF 39.1%. Melts in your hand. In: Partly distorted structure due to incompletely ionised atoms. BCN 4+8. PE 68.6%. Oxides in preferred +3 state are weakly amphoteric; forms anionic indates in strongly basic solutions. Tendency to form covalent compounds is one of the more important properties influencing its electro-chemical behaviour. Sn: Irregularly coordinated structure associated with incompletely ionised atoms. BCN 4+2. PF 53.5%. Oxides in preferred +2 state are amphoteric; forms stannites in strongly basic solutions. Grey Sn is electronically a zero band gap semimetal, although it behaves like a semiconductor. Diamond structure. BCN 4. PF 34.0%. Pb: Close-packed, but abnormally large inter-atomic distance due to partial ionisation of Pb atoms. BCN 12. PF 74%. Oxide in preferred +2 state is amphoteric; forms anionic plumbates in strongly basic solutions. Bi: Electronic structure of a semimetal. Open-packed structure (3+3) with bonding intermediate between metallic and covalent. PF 44.6%. Trioxide is predominantly basic but will act as a weak acid in warm, very concentrated KOH. Can be fused with KOH in air, resulting in a brown mass of potassium bismuthate.

Seaborg line: No f electrons in gas phase La, Ac and Th atoms.

Triple line: N = gas; S = solid; Br = liquid.

Zigzag lobby: H needs no intro. Li: Many salts have a high degree of covalency. Small size frequently confers special properties on its compounds and for this reason is sometimes termed 'anomalous'. E.g. miscible with Na only above 380° immiscible with molten K, Rb, Cs, whereas all other pairs of AM are miscible with each other in all proportions. Be: Has a covalent component to its otherwise predominately metallic structure = low ductility. Lowest known Poisson's ratio of elemental metals. Amphoteric; predominately covalent chemistry atypical of group 2. Some aspects of its chemical properties are more like those of a metalloid.

Zigzag line: Eponymous metal-nonmetal dividing line.

Zintl line: Hypothetical boundary highlighting tendency for group 13 metals to form phases with a various stoichiometries, in contrast to group 14+ that tend to form salts with polymeric anions.

* BCN = bulk coordination number

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Year:  2020 PT id = 1174

Split s-, p- & d-Block Periodic Table

René Vernon presents a periodic table formulation with split s-, p- & d-blocks.

The details: Group 3 as B-Al-Ga-In-Tl

Al over Sc has some history, which seems to have been forgotten.

Here are some other tables with B-Al-Sc-Y-La:

What was it that these luminaries knew about B-Al-Sc-Y-La-Ac that is deemed to be no longer relevant, and why is that the case?

Deming (1947, Fundamental Chemistry, 2nd ed. p. 617) located Al with the pre-transition metals in groups 1?2. Cox (2004, Inorganic Chemistry, 2nd ed. p. 185) refers to the pre-transition metals as those in groups 1 and 2, and Al. Here's that 2019 periodic table (by me), recording oxidation number trends, further suggesting B and Al are better placed over Sc.

In this vein, Rayner-Canham (2020, The periodic table: Past, present, and future, pp. 178–181) writes:

"It was Rang in 1893 who seems to have been the first, on the basis of chemical similarity, to place boron and aluminum in Group 3.

"Such an assignment seems to have been forgotten until more recent times. Greenwood and Earnshaw have discussed the way in which aluminum can be considered as belonging to Group 3 as much as to Group 13 particularly in its physical properties. Habashi has suggested that there are so many similarities between aluminum and scandium that aluminum's place in the Periodic Table should actually be shifted to Group 3.

"In terms of the electron configuration of the tripositive ions, one would indeed expect that Al3+ (electron configuration, [Ne]) would resemble Sc3+ (electron configuration, [Ar]) more than Ga3+ (electron configuration, [Ar]3d10). Also of note, the standard reduction potential for aluminum fits better with those of the Group 3 elements than the Group 13 elements (Table 9.2) – as does its melting point.

"In terms of their comparative solution behavior, aluminum resembles both scandium(III) and gallium(III). For each ion, the free hydrated cation exists only in acidic solution. On addition of hydroxide ion to the respective cation, the hydroxides are produced as gelatinous precipitates. Each of the hydroxides redissolve in excess base to give an anionic hydroxo-complex, [M(OH)4]... There does seem to be a triangular relationship between these three elements. However, aluminum does more closely resemble scandium rather than gallium in its chemistry. If hydrogen sulfide is bubbled through a solution of the respective cation, scandium ion gives a precipitate of scandium hydroxide, and aluminum ion gives a corresponding precipitate of aluminum hydroxide. By contrast, gallium ion gives a precipitate of gallium(III) sulfide. Also, scandium and aluminum both form carbides, while gallium does not."

To answer my own question as to why group 3 as B-Al-Sc-Y-La-Ac has been forgotten.

I suspect what happened is that it was historically known that group 3 was better represented as B-Al-Sc-Y-La-[Ac]. Then, with the advent and rise of modern electronic structure theory, B-Al- got moved to the p-block because, after all, they were p-block elements, never mind the damned chemistry. And La stayed in the d-block since it was the first element to show 5d electron, and 4f did not show until Ce. And Lu stayed where it was since even thought it was learnt that the f shell become full at Yb, rather than Lu, nothing changed about the chemistry of Lu. Nowadays, this has all been forgotten.

The modern periodic table is a chemistry-physics hybrid.

Lu in group 3 demands He over Be. La in group 3 demands B-Al over Sc. Neither option gets up. The more important consideration is to teach the history and have students and chemists appreciate both perspectives.

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Year:  2020 PT id = 1175

Rainbow Periodic Table in ADOMAH Cube

From the prolific Nagayasu Nawa, a version of his Rainbow Periodic Table inside Valery Tsimmerman's glass cube:

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Year:  2021 PT id = 1181

Understanding Periodic and Non-periodic Chemistry in Periodic Tables

Cao C, Vernon RE, Schwarz WHE and Li J (2021). Front. Chem. 8:813.


The chemical elements are the "conserved principles" or "kernels" of chemistry that are retained when substances are altered. Comprehensive overviews of the chemistry of the elements and their compounds are needed in chemical science. To this end, a graphical display of the chemical properties of the elements, in the form of a Periodic Table, is the helpful tool. Such tables have been designed with the aim of either classifying real chemical substances or emphasizing formal and aesthetic concepts. Simplified, artistic, or economic tables are relevant to educational and cultural fields, while practicing chemists profit more from "chemical tables of chemical elements."

Such tables should incorporate four aspects:

(i) typical valence electron configurations of bonded atoms in chemical compounds (instead of the common but chemically atypical ground states of free atoms in physical vacuum);

(ii) at least three basic chemical properties (valence number, size, and energy of the valence shells), their joint variation across the elements showing principal and secondary periodicity;

(iii) elements in which the (sp)8, (d)10, and (f)14 valence shells become closed and inert under ambient chemical conditions, thereby determining the "fix-points" of chemical periodicity;

(iv) peculiar elements at the top and at the bottom of the Periodic Table.

While it is essential that Periodic Tables display important trends in element chemistry we need to keep our eyes open for unexpected chemical behavior in ambient, near ambient, or unusual conditions. The combination of experimental data and theoretical insight supports a more nuanced understanding of complex periodic trends and non-periodic phenomena.

Thanks to René Vernon for the tip.

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Year:  2021 PT id = 1183

Crustal Abundance vs. Electronegativity

A chart by René Vernon of Elemental Abundance (g/kg log10) vs. Electronegativity, H to Bi.

René writes:

Below is a remarkable XY chart where x = electronegativity and y = crustal abundance (log10). It stops at the end of the s-process, at Bi. The abundance figures are from the CRC Hanbook of Physics and Chemistry (2016-2017).

I say remarkable as I had little idea what the chart would end up looking like when I started plotting the values.

As well as its coloured regions, I've marked out track lines for six of the main groups and one for group 3.


The rose-coloured arc on the left encompasses the pre-transition metals i.e. the alkali and alkaline earth metals and aluminium, followed by, in the orange rectangle, the rare earth metals. Opposite these regions, along the southern boundary of the green paddock, are the halogens.

In the pale yellow field sheltered by the pre-transition metals and the REM, are the 3d transition metals and, in the white corral, are 4d and 5d base transition metals. Opposite these regions, in the green paddock, are the core nonmetals H, C, N, O, P and S, with Se as an outlier.

Following in the grey blob are the post-transtion or poor metals, immediately adjacent to the bulk of the metalloids or poor nonmetals.

Finally, in the light blue patch, the noble metals are complemented by the noble gases frolicking in the open.

Abundance tends to decrease with increasing Z. Notable exceptions are Li, B, N and Si.



I was intrigued by the article referring to Ni and Ar, and the suggestion of Ar becoming somewhat anionic, albeit in extreme conditions (140 GPa, 1500 K)



I wasn't looking for these but they at least exist as follows:

My references are:

Thus the abundance of the metals in the crust tends to fall with increasing EN.

An answer from L. Bruce Railsback, creator of the Earth Scientist's Periodic Table

"I think I can answer one of the questions. 'Why is Si good at forming a planetary crust?' – because it's so bad at staying in the core. Silicon isn't sufficiently metallic to stay in the core. Even in the mantle and crust, it doesn't go into non-metal solids well: in cooling magmas, it's only a lesser member of the early-forming minerals (e.g., Mg2SiO4, forsterite, where it's outnumbered two to one). The mineral only of Si as a cation, SiO2 (quartz), is the LAST mineral to form as a magma cools, in essence the residuum of mineral-forming processes. At least some this thinking is at Bowen's Reaction Series and Igneous Rocks at"

Which Electronegativity Scale?

The wide variety of methods for deriving electronegativities tend to give results similar to one another.

Click to enlarge:

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Year:  2021 PT id = 1184

van Spronsen's Periodic Table: Update

René Vernon writes:

I'd never before realised how clever van Spronsen's 1969 Periodic Table is. It seems to be the ultimate logical electronic version, informed by the actual filling sequence in the gas phase atoms, rather than the idealised sequence.

So, H-He are over Li-Be.

Group 3 is Sc-Y-La-Ac since that is where the d-shell starts filling. In the rest of the d-block, there are (4+1) x d5 and (4+2) x d10.

The f-block starts with Ce, as that is where the f-shell starts filling. Notice the high degree of regularity with the 4 x f7 and the 4 x f14, and how Th is treated i.e. as 5f0.

After DIM's 8-column form, I believe the periodic family tree now looks like this:

Three split-blocks
1a. He over Ne; B-Al over Sc-Y-La-Ac = old school form
1b. H-He over F-Ne; ditto = e.g. Soddy 1914?, Kipp 1942?

Two split blocks
2a. He over Ne; group 3 as Sc-Y-La-Ac = popular form

One split-block
3a. He over Ne; group 3 as Sc-Y-Lu-Lr = Lu form 3b. He over Be; group 3 as Sc-Y-La-La = forgotten van Spronsen form

No split blocks
4. He over Be = Janet equivalent

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Year:  2021 PT id = 1186

Helix vs. Screw

Julio Antonio Gutierrez Samanez writes:

Until today, when they write about the work of Chancourtois and his telluric helix wound in a cylinder, still no one alludes to this other telluric helix wound in a cone or screw, the idea is the same: a rope that winds a geometric solid.

The first was devised in 1862, the other in 2008 (146 years later). But, there is a big epistemological difference. In the first, the elementary series presented was: 8, 8, 8, 8, 8 ..., etc., in the second it is: 2, 2, 8, 8, 18, 18, 32, 32. Furthermore, the division of conical radii is regulated by the function 2 (n ^ 2) = 2, 8, 18, 32...

Each binode has two spirals or two periods with the same number of elements, which correspond to the function 4 (n ^ 2). I don't think it is a discovery, it is just the conclusion of the contributions of Rydberg, Janet, and, of course, Chancourtois.

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Year:  2021 PT id = 1187

Aufbau Periodic Table

An Aufbau Periodic table designed by Steven Muov at

Steven writes:

"Science has aptly been described as a search for order in the Universe. It follows that chemistry is a search for order in matter. While the search will always be a work in progress, great strides towards the finding of order in matter resulted in 1869 when Dimitri Mendeleev stood on the shoulders of many others and published his periodic table. The table has since been modified and improved but still has a remarkable resemblance to the original Mendeleev table. Excellent compilations of many alternate periodic tables have been published that use novel and intriguing approaches (e.g., circles, spirals and 3d, but the contemporary versions of the Mendeleev table are the charts found on the walls of thousands of lecture rooms around the world. The periodic table deserves recognition as one of the milestones of science along with contributions from other sciences including but not limited to: physics by Newton and Einstein, biology by Darwin, Rosalind Franklin, Watson and Crick, astronomy by Copernicus and Galileo and geology by Wegener..."

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Year:  2021 PT id = 1191

Provisional Report on Discussions on Group 3 of The Periodic Table

Provisional Report on Discussions on Group 3 of The Periodic Table by Eric Scerri, De Gruyter | 2021


The following article is intended as a brief progress report from the group that has been tasked with mak-ing recommendations to IUPAC about the constitu-tion of group 3 of the periodic table ( It is also intended as a call for feedback or suggestions from members of IUPAC and other readers.

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Year:  2021 PT id = 1197

Nawa's Multi Periodic Table

Nagayasu Nawa - "A Japanese school teacher and periodic table designer" - has developed a "Multi" Periodic Table with three formulations: long-form, upsidedown long-form & circular with era of discovery, electronic structure and abundance data.

Click here to download the .pdf file.

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Year:  2021 PT id = 1203

Vernon's CSF Left-Step Periodic Table.

René Vernon's CSF Left-Step Periodic Table.

"I was prompted to switch to He-Be and [to develop a Janet type] left-step periodic table. I suggest it remediates concerns about H and He, and Lu in group 3.



Click here to enlarge:

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Year:  2021 PT id = 1204

Cubical-Stair Periodic Table

Sarthak Gupta's Cubical-Stair Periodic Table (Into a Whole New Dimension):

"Looking at the Modern periodic Table, somethings always bug you. The huge gap between the s and p-block when they should be side by side. The whole f-block floating around in air when it should be there in period 6 and 7. So why not experiment with shapes and structures and come up with something more space efficient?

"The cubical Periodic table paves the way taking the periodic table into a whole new dimension. Yes! from the 118 squares, we are going to transition into 67 cubes stacked onto each other like stairs."

The Cubical-Stair Periodic Table Explained:

Advantage over the Modern PT

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Year:  2021 PT id = 1210

Vernon's Eight-Fold Way Periodic Table

René Vernon suggests that the chemical elements can be grouped into eight classes: four metallic (Active, Transition, Post-Transition and Noble) and four non-metallic (Halogen, Biogen, Metalloid and Noble gas):

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Year:  2021 PT id = 1212

Term & Spin State Periodic Table

A Tern & Spin State periodic table by Gnanamani Simiyon who writes:

"We tried to arrange the elements based on the ground state term and spin state. I attached picture of the periodic table drawn. For example, I notice that alkali metals and coinage metals grouped up indicating some relationship between the groups. Similarly with respect to alkaline Earth metals and Zinc group. We are unable to further understand other groupings based on the ground state term and spin state."

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Year:  2021 PT id = 1213

Mendeleyev Revisited

An Open Access paper: Marks, E.G., Marks, J.A. Mendeleyev revisited. Found Chem 23, 215-223 (2021).

"Despite the periodic table having been discovered by chemists half a century before the discovery of electronic structure, modern designs are invariably based on physicists' definition of periods. This table is a chemists' table, reverting to the phenomenal periods that led to the table's discovery. In doing so, the position of hydrogen is clarified."

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Year:  2021 PT id = 1217

History [of the] Elements and Periodic Table

From the Royal Society of Chemistry (RSC) an interactive Elements and Perioid Table History web page:

Thanks to Eric Scerri for the tip!

See the website and Eric's Twitter Feed.

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Year:  2021 PT id = 1218

Mendeleyev-Sommerfeld IUPAC Periodic Table

From John Marks' updated Mendeleyev-Sommerfeld IUPAC Periodic Table.

John writes:

This is an adaptation of Fig. 4 [from] to match IUPAC's 18-column table. The yellow (transition metals) are Sommerfeld's 'A'-subgroups and the green (rare earths) are Sommerfeld's 'B'-subgroups.

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Year:  2021 PT id = 1219

Discoid Periodic Table of The Elements

Statement: "The orbital periodicity of the elements are the periodic function of their atomic number." By Muzzammil Qureshi.

Muzzammil writes:

"Years before Mendeleev's publications, there was plenty of experimentation with alternative layouts for the elements. Even after the table got its permanent right-angle flip, folks suggested some weird and wonderful twists.

"One of them are Circular in shapes. Discoid means circular in shape, and there is a great reason for choosing such a shape. The term "Periodicity" itself means "To occur in intervals", and if you walk around in a circle, you will find that you will return to the point from where you started at. Similarly, if the elements are also arranged in such way, then we shall experience more periodicity in the elements than before..."

Read more here...

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Year:  2021 PT id = 1222

Rolled-up Version of Benfey's Periodic System

Rolled-up Version of Benfey's Periodic System by Julio Antonio Gutiérrez Samanez. More on the YouTube video here.

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Year:  2021 PT id = 1224

Quantum Periodic Table

Shriya Tiwari & D. K. Awasthi, Quantum Periodic Table, wjpmr, 2021, 7(4), 124-130

The authors write:

"In [the] quantum periodic table, The elements are arranged according to the order of electron-shell filling, by classifying the energy levels of the atoms in the order they are filled, to create a layout based on electronic configuration. The classification of the elements is done purely on the basis clarified above, without giving any weight age to the atomic numbers. With the advent of electronic configurations and quantum mechanics, many attempts have been tried in this periodic table to unlock all the problems related with the placement of elements, which have been remained as the topic of debate by generations of chemists."

Read more in the paper here.

Click PT image to enlarge:

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Year:  2021 PT id = 1225

Hutcheon Right Step Periodic Table

From Scott Hutcheon's Linkedin Website:


"Built from first principles, the RSPT is the only Periodic Table (so far) that reflects the periodicity of radioactive elements (natural and artificial) including Tc-Np and Cf/Es, the periodicity of liquids and gases (at standard and other conditions), depicts the 5 and 8 mass roadblocks, and finally clarifies the positions of the initial propagating elements H, He, and Li-Be/B in accordance with their cosmic and stellar evolutionary origins.

"Name inspired by the Janet Left Step Periodic Table (LSPT).

"Bonus Easter Egg: SPOCH BONSe, pronounced Spock Bones, is a new mnemonic device to remember the updated elements considered most essential for human life. Also considered POSCH SeNOB and SNOBS ePOCH."

Click PT image to enlarge:

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Year:  2021 PT id = 1232

The Periodic Table: Is it Perfect, is it Fractured or is it Broken?

A video from Mark Leach, who writes:

The periodic table is an icon of science. Indeed, all chemical matter is made from periodic table stuff. The periodic table of the elements is often presented as being:

However, the chemistry of the chemical elements is actually a little more complicated than this. So, where & why does the predictability 'break'?

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Year:  2022 PT id = 1228

Hutcheon's Animated Formulation(s) of The Periodic Table

A very cool animated periodic table that shows the PT morphing between various formulations. Read more on Scott's Linkedin Page.

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Year:  2022 PT id = 1229

Kudan's Left-Step Periodic Table

From Pavel Kudan, a specialist in mass-spectrometry and identification of compounds., who suggests a variant of the left-step Periodic table:

1. Energy barriers directly shown to express correctly the Periodic Law
2. 4 periods (8 half periods)
3. 21 groups (1a-8a, 2b-8b, 3c-8c)
4. f-elements classified by groups, not families
5. La/Ac and Lu/Lr both in 3rd group
6. Cu/Ag/Au/Rg in group 8b together with Ni/Pd/Pt/Ds

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Year:  2022 PT id = 1230

Kudan's Left-Step Periodic Table (Short Form)

From Pavel Kudan, a specialist in mass-spectrometry and identification of compounds., who suggests a short-form variant of his left-step Periodic table:

1. Energy barriers directly shown to express correctly the Periodic Law
2. 4 periods (8 half periods)
3. 21 groups (1a-8a, 2b-8b, 3c-8c)
4. F-elements classified by groups, not families
5. La/Ac and Lu/Lr both in 3rd group
6. Cu/Ag/Au/Rg in group 8b together with Ni/Pd/Pt/Ds
7. Reminders for H to group 7a, He to group 8a, Cu/Ag/Au/Rg to group 1b

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Year:  2022 PT id = 1231

Kaleidocycle of the Periodic Table

Pablo Cassinello provides a "Three-dimensional figure to improve the didactics of the Periodic Table", a Kaleidocycle of the Periodic Table.

There is a full article about this dynamic, three dimensional formulation in Pablo's blog in Chem Ed Xchange, including instructions on how to make the object.

Pablo writes:

"A kaleidocycle has four different faces, each one made of a juxtaposition of rhombuses. By turning it you can easily choose one of the four faces. On these, four different pictures can be displayed. In this three-dimensional figure of the periodic table are the elements organized in four blocks according to their final electronic structure. It is intended that students with this playful figure actively participate in classes by rotating their kaleidocycle looking for the groups or elements that are being studied. The entire periodic table fits in one palm of their hands. It is also a didactic device because students only focus their attention on one block or group of elements from the entire Periodic Table. It can be a more entertaining, motivating and exciting way of learning about the subject of the Periodic Table."

Thanks to René for the tip!

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Year:  2022 PT id = 1234

Kudan's Periodic Law (Helix Form)

From Pavel V. Kudan, a specialist in mass-spectrometry and identification of compounds, who suggests a helical variant of the Periodic table. The graphical representation illustrates the Periodic Law and the following features of the Kudan’s periodic system:

    1. Four element periods (1, 2, 3, 4)
    2. Two element half periods (-,+)
    3. Twenty one element subgroups octet rule compatible (1a-8a, 2b-8b, 3c-8c)
    4. Small energy barriers between S and F, F and D, D and P elements (gray segments)
    5. Large energy barriers between P and S elements (black segments)
    6. Large energy barrier between He and Li (black segments)

(See also Kudan’s Left-Step Periodic Table)

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Year:  2022 PT id = 1236

Which Element is the Best?

The That Chemist YouTube channel asks "Which Element is the Best? Elements 1-20 & Elements 21-40"

That Chemist is a synthetic organic chemist and his bias is in that direction although he gives a variety of examples:

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Year:  2022 PT id = 1239

Tassitus' Periodic Table

By Harry Tassitus who wites:

"Here is my narrative; After 50 years of study I have released this periodic table which is a synthesis of the work of Dr Isaac Asimov, Dr Ida Noddack, and Edward g. Mazurs, the latter of which I found on the Internet Database of Periodic Tables web site."

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Year:  2022 PT id = 1250

Makeyev's Relativity Matrix of the Elements of Matter (MOEM)

By Alexander K. Makeyev, a member of the Moscow Society of Naturalists, multidisciplinary researcher and inventor; the author of Theory Relativity of Reality: The Relativity Matrix of the Elements of Matter (MOEM)

"Periodic table of elements vertical form. The periods of atomic levels of dense matter of matter correctly end at the element of the group of alkaline earth metals. Symbols of timelessness-non-existence / time-being are displayed in front of hydrogen; loose matter of vacuum and electrostatics and magnetism of ether; dense matter of neutronium (neutron nuclei of atoms and neutron stars)."


  1. Makeev A.K. Julius Lothar Meyer was the first to build a periodic system of elements // European applied sciences, No. 4 2013, (April) volume 2. - pp. 49-61. ISSN 2195-2183.
  2. A.K. Makeev. Self-reproduction of matter // Materials of the international scientific-practical conference: "Prospects for the Development of Modern Science" – Jerusalem, Israel: Regional Academy of Management, 2016. – 535 p. P. 213-220. UDC 001.18 BC 72 P 93 ISBN 978-601-267-398-2
  3. A.K. Makeev. The essence of time. //
  4. A.K. Makeev. What is the natural ending of periods? //
  5. A.K. Makeev. Is hydrogen a dielectric gas or an alkali metal? //
  6. A.K. Makeev. Do vacuum and ether participate in gravity? //
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Year:  2022 PT id = 1252

Vernon's Yin Yang of The Periodic Table

René Vernon writes:

"I was prompted to [develop] this item after reading Eric Scerri's open access article: In Praise of Triads. The nub of Eric’s article is to argue for the LST on the grounds of triad regularity, first-row-anomaly regularity, and consistency with QM.

"It occurs to me that efforts to introduce more regularity to the PT invariably introduce new irregularities elsewhere. For example, as far as triad regularity goes, the left step table (LST) with He over Be introduces its own anomaly in that no element in period 1 (H, He) is part of a triad whereas this is not the case for all periods thereafter. In contrast, all periods of the traditional table have at least one element that is part of a triad.

"As far as QM goes, this tells us that there is a theoretical regularity to the PT. This regularity can be used to inform e.g. the LST, ADOMAH or Julio’s binodes. But such depictions do not reflect the factual relationships we see amongst the chemistry of the elements as well as is the case for the conventional form. A most obvious example is that the LST, while being more consistent with QM, disrupts the bottom-left to top-right trend in metallic to nonmetallic character seen in conventional tables.

(I must caveat that I'm referring to the chemistry of the elements in conditions regularly occurring on Earth. For example, it has been reported that under sufficiently high pressures the elements change their EN and electron configurations. If so, this suggests a need for a different table at high pressure.)

At this point, the chemistry educators enter the picture. They move the s-block to left. Helium is relocated over Ne on the basis of its nobility. (This could change if a few compounds of He were to be synthesized). Somewhat similarly, La was discovered well before Lu, so it ended up under Y, and most folks see no good reason to replace La with Lu. Sure, in the 32-column form, the result is a split d-block but the infrequency with which the 32-column form appears is such that most people are not bothered. The result is the conventional table.

Philosophically, while the n+l based LST might represent the most general form of table, the conventional table appears to currently represent the most pragmatic derivation for chemists and chemistry educators.

Since the PT is classification rather than theory, and there will thus always be hard cases at the boundaries, there will invariably be minor variations in the depiction of the conventional table with respect to e.g. the placement of H, the composition of group 3, or the length of the f block.

And there will always be tables such as MR that focus on particular perspectives of relationships among the the elements.

I’ve tried to sketch what's going in the attached image:"

Click to enlarge.

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Year:  2022 PT id = 1253

Gorodkov's Periodic System of Periodic Systems

Mikhail Gorodkov writes:

"I hope you'll find attached version of Periodic System not only funny but also informative!"

Click to enlarge:

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Year:  2022 PT id = 1254

99 Elements Sorted by Density & Electronegativity

René Vernon writes:

"A little while I ago I noticed that a scatter plot of EN (revised Pauling) and density values of the elements resulted in a nice distribution, as per the table below.

"According to Hein and Arena (2013) nonmetals have low densities and relatively high EN values; the table bears this out. Nonmetallic elements occupy the top left quadrant, where densities are low and EN values are relatively high. The other three quadrants are occupied by metals. Of course, some authors further divide the elements into metals, metalloids, and nonmetals although Odberg argues that anything not a metal is, on categorisation grounds, a nonmetal.

Note 25 says:

(a) Weighable amounts of the extremely radioactive elements At (element 85), Fr (87), and elements with an atomic number higher than Es (99), have not been prepared.
(b) The density values used for At and Fr are theoretical estimates.
(c) Bjerrum (1936) classified "heavy metals" as those metals with densities above 7 g/cm^3.
(d) Vernon (2013) specified a minimum electronegativity of 1.9 for the metalloids.

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Year:  2022 PT id = 1257

Tutti Frutti Periodic Table

René Vernon who writes:

"As a potentially powerful teaching and learning instrument: a Tutti Frutti periodic table. I feel younger folk [will] be delighted by it. The overlay of electron configurations and blocks was designed by a colleague of mine."

Click to enlarge:

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Year:  2022 PT id = 1259

Deming's 1923 Periodic Table, Updated by Vernon

René Vernon writes:

"Here is the 21st century version of Deming's 1923 formulation. Lacking elegance perhaps, but that’s messy chemistry for you. 25 columns wide rather than 18 or 32. Split s, p and d blocks. The connecting lines are based on four sources:

    1. Deming
    2. The literature since his time, as shown
    3. The expected behaviour of the super-heavy elements
    4. The smoothness of Z vs physiochemical property trendlines going down groups, for up to 40 physiochemical properties

"I used [the term] frontier metals to refer to the post-transition metals, since the latter term has never applied well to Al. The frontier adjective comes from a line by Russell and Lee in which they refer to Bi and Po occupying frontier territory on the PT, adjacent to the nonmetals (2006, p. 419).

"As far as metalloids are concerned, Dingle nicely summarized their status: "With ‘no-doubt' metals on the far left of the table, and no-doubt non-metals on the far right…the gap between the two extremes is bridged first by the poor (post-transition) metals, and then by the metalloids— which, perhaps by the same token, might collectively be renamed the 'poor non-metals'." (2017, p. 101)

Ref: Dingle 2017, The Elements: An Encyclopedic Tour of the Periodic Table, Quad Books, Brighton Russell AM & Lee KL 2005, Structure-Property Relations in Nonferrous Metals, John Wiley & Sons, Hoboken, NJ

Click to enlarge

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Year:  2022 PT id = 1275

777 Periodic Wedding Cake

René Vernon's version of Courtine’s flat projection (1926) of his periodic tower, the 777 Periodic Wedding Cake:

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Year:  2022 PT id = 1276

Periodic Table of Periodic Tables

René Vernon has collected the PT formulations in this PT database and classifed them as:

Short, Triangular, Medium, Long, Continious, Folding, Spatial & Unclassified

and tabulated them by date. The 'working document' is currently a word file.

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Year:  2022 PT id = 1277

Ramsay-Sommerfeld Periodic Table

John Marks has updated Scerri's 2006 Triad formulation. Marks writes:

"[This is] an expansion of Scerri´s 2006 triad formulation, but brings the lanthanides & actinides in from the cold. It is lso modelled on the way IUPAC constructed its 18-group PT (but with traditional group numbering), that is to say, the total of 22 groups is simply IUPAC's 18 plus the four extra f-groups. I am not sure if this counts as a "medium" or a "long" form.

"If this PT needs a name, it would be the Ramsay-Sommerfeld PT. It has Ramsay´s 1915 arrangement for H (copied by Eric Scerri in 2006) and Sommerfeld's "greater" and "lesser" periods (1916) in green and yellow respectively. It solves the 'exile' of the f-blocks without making it too unwieldy (22 instead of 32 groups). The yellow (transition series) are Sommerfeld's 'A' subgroups and the green (rare earth series) are Sommerfeld's 'B' subgroups."

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Year:  2023 PT id = 1274

DALL·E Pop Art Periodic Table

I asked DALL·E to generate a: "periodic table as pop art", and the AI produced this:

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Year:  2023 PT id = 1279

Mendeleyev’s Periodic Table after Ramsay & Sommerfeld

John Marks, who provided the graphic, writes:

"This is the Ramsay-Sommerfeld PT and would seem to be the definitive PT, at least historically.

"Ramsay, a chemist, completed Mendeleyev's PT with the discovery of the inert gases in the 1890s and the position of hydrogen with the halogens by 1915.

"Sommerfeld, a physicist, generalized Bohr's atom in 1916 to yield the s-, p-, d- and f- electronic subshells that determine the layout of physicists' PTs, in particular their first "very short" period comprising H and He. Sommerfeld also explained the 'long periods', viz. the transition series ('A' subgroups) and the 'very long periods', viz. the rare earth series ('B' subgroups).

"In this chemistry/physics hybrid periodic table, the physicist Sommerfeld's first ('very short') "period" is subsumed under the chemist Ramsay's first two groups (-1 and 0) which are distinguished by colour: group -1 is white = 1s1p5, viz. H & the halogens; group 0 is black = 1s2p6, viz. He & the inert gases.

"Einstein's demonstration of atomic reality in 1905 (phenomena verified by Perrin in 1908) established the basic units of the paradigm of chemistry. Rutherford and Bohr (both physicists) went inside the atom, into the paradigm of physics.

"The PT thus straddles the borderland of the two paradigms of physics and chemistry and this has contributed significantly to the long debates on the form of the PT."

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Year:  2023 PT id = 1280

Marks' Version of Mendeleyev's 1869 Formulation

John Marks, who provided the graphic, writes:

"I went back to Mendeleyev´s 1869 original and drew this (below) which demonstrates the Sommerfeldsche aufspaltung as occurring after completed s-subshells. No-one disputes the chemical phenomena of the octets formed by He/Ne, Li/Na, Be/Mg, B/Al, C/Si, N/P and O/S nor that H/F occurs at the beginning of these octets, however "irregular" H may appear.

"Chemical periodicity is clearly based on periods arising from sp3 hybridization and the aufspaltung appears to occur between the s and the p3. This gives rise to the positions of Sommerfeld's "Long" (with the d-elements) and "Very Long" (with the f-elements) periods."

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Year:  2023 PT id = 1283

Element Names: The Etymology of The Periodic Table

An excellent video by RobWords about the names of the chemical elements and how they came about:

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Year:  2023 PT id = 1285

Kudan's Periodic System

From Pavel V. Kudan, a specialist in mass-spectrometry and identification of compounds, who suggests new periodic table based on new formulation of the periodic law.

See also:

Kudan's Periodic Law (Helix Form)

Genoma de la Materia

Click the image to enlarge.

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Year:  2023 PT id = 1286

Six Stages of The Convergence of The Periodic System

Bran, A.M., Stadler, P.F., Jost, J. et al. The six stages of the convergence of the periodic system to its final structureCommun Chem 6, 87 (2023).

Abstract (abridged):

"We show, by analysing the space between 1800 and 2021, that the system has converged towards its current stable structure through six stages, respectively characterised by the finding of elements (1800–1826), the emergence of the core structure of the system (1826–1860), its organic chemistry bias (1860–1900) and its further stabilisation (1900–1948), World War 2 new chemistry (1948–1980) and the system final stabilisation (1980–)."

Periodic tables representative of each period in history. Families of similar elements (sets sharing colour) shown in each table summarise the patterns and do not necessarily imply continuity nor simultaneity of the families throughout the period:

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Year:  2023 PT id = 1287

Semicircular Hybrid Chart of the Nuclides

Nawa Nagayasu has produced a new version of the Segrè Chart of the Nuclides.

Nawa writes:

"The chart has the number of neutrons on the [curved] horizontal axis and the number of protons (atomic number) on the vertical axis. I used the IAEA colour coding [scheme]. JAEA's half-life ranks are indicated by simple numbers, not rounded frames.

"In order to fit the whole chart into a semicircle, the axis representing the number of neutrons was made a spiral-like curve. For clarity, the number of neutrons is shown in the middle of each curve."

Yuri Oganessian has commented:

"Nawa Nagayasu is an original and talented designer. After all, it is not easy to work with 118 elements, but now also with isotopes, of which there are more than 3000. The fan design looks attractive and this is very important. This will make people, especially school age, guess the numbers that are written there. So they will gradually delve into the content of the Table, a truly brilliant creation."

Click image to enlarge

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Year:  2023 PT id = 1288

Holistic View of Metals & Nonmetals: Exploded View

From Organising the metals and nonmetals: An update by René Vernon from the chemrxiv preprint server.

Rene writes:

Abstract: This paper updates my 2020 article, Organising the metals and nonmetals in which I advocated for parsing the periodic table into four kinds of metals and four of nonmetals. This framework is retained and updated, and augmented with some additional chemistry-related and philosophical observations.

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Year:  2023 PT id = 1289

Chemdex: Valence & Oxidation Number Trends

From Mark Winter's review paper Chemdex: quantification and distributions of valence numbers, oxidation numbers, coordination numbers, electron numbers, and covalent bond classes for the elements Dalton Trans., 2024,53, 493-511

The images below show the Valence number (VN) and oxidation number (ON) proportions as percentages for the elements; and Periodic tables displaying valence number proportions (%). (There are few data for Pm and no data for Fr and elements beyond Es.)

The position of H and the group numbers are addressed in the paper.

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Year:  2024 PT id = 1298

Kudan's 3D Model of The Periodic Table

Pavel V. Kudan's 3D model of the Periodic Table via direct download.

Parvel writes:

"The shape of this 3D model allows to show most important thing – H may be aligned over F-Ts and He may be aligned over Ne-Og without classification of H to group F-Ts or He to group Ne-Og. To see that it is needed only that cylinder to be tough (hard) and flat parts to be flexible with ability to change angle. Than is important because according Mendeleev’s principle, maximum valence is main for grouping elements and it is controversial to have element with maximum valence 2 between elements with maximum valence 8.

"Coloring He as gray in the 3D model just reflex the fact that it goes just before the energy gap, as well as coloring Ne-Og in gray show that they too go just before the energy gaps, which makes He and Ne-Og noble. The main is not coloring, but the ability to align and demonstrate.

"You may also remember that the issue of opening the new IUPAC Group 2 project to discuss He group as a continuation of the IUPAC Group 3 project has already been raised in e-mail correspondence with IUPAC some time ago in protection of our reconstruction of Landau’s geometry of the Periodic table.

"I agree with you that double periodicity is important, but also rearrangements of electronic configurations caused by properties of d-orbitals also must be taken in account. For example, Cu has valences 1 or 2, Zn has valence 2 due to special properties of d-orbitals. The 3D model of the Periodic table separates the ability of d-orbitals to steel electrons from s-orbitals and f-orbitals causing of such effects.

"Also when you will have a copy of the 3D model you will see that it unifies both geometry of the Mendeleev’s Periodic table and geometry of the Janet’s Periodic table. Following anticlockwise you may see Mendeleev’s order while following clockwise you may see Janet’s order. It is similar to having the 3D moles of globe as visual aid for better vision of Mendeleev’s Periodic table and Janet’s Periodic table as flat detailed maps."

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Year:  2024 PT id = 1303

Bilateral Symmetry in the Periodic Binodic Table

René Vernon, who developed these ideas, writes:

This table is adapted from the work of Gutiérrez-Samanez (2020), who discusses mathematising the chemical periodic system as a grid, which leads to a quadratic function or “binódica function” formed by pairs of periods or binodos (dyads).

The difference is that whereas Gutiérrez-Samanez showed the first pair of periods as H-He and Li-Be, this table shows the first period as e-n and H-He. Here, e is the electron and n is the neutron. Each pair of periods is shown pancake style rather than in a single row. The formula for the length of each paired period or binode is 2n2 = 2, 8, 16, 32.

The idea of paired periods has a long history; it seems to have originated with Werner in 1905.

According to Jensen:

"The temptation to read more into the shape of the table than is really there is almost overwhelming. Even someone as great as Werner was tempted (1905). Having postulated a missing element between H and He, he decided to perfect the symmetry of his table by guaranteeing that rows of differing length always occurred in pairs. Consequently, he further postulated a row of three missing elements lying above the H-X-He row."

Rydberg (1913, pp. 12–13) used a formula 4n^2 for the number of elements in the paired periods: 4, 16, 32, 64. This formula is also used by Gutiérrez-Samanez.

Paired periods were also used by Janet (1928), Saz (1931), Achimov (1946) and Baca Mendoza (1953).


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Year:  2024 PT id = 1304

Marks' Aufspaltung Formulation

John Marks' Aufspaltung (or "Splitting") formulation, after Mendeleyev (1869), Ramsay (1915) & Sommerfeld (1916).

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Year:  2024 PT id = 1307

Cylindrical Periodic Table with Seven Vertical Columns

The Cylindrical Periodic Table with Seven Vertical Columns by Laith H. M. Al-ossmi, College of Engineering, University of Thi-Qar, Iraq; Thi-Qar University Pres. Read the full paper here.

Abstract: In this article, a new model of the periodic table in cylindrical form wrapped around its outer circumference is presented, departing from the traditional periodic table of elements adopted by the International Union of Pure and Applied Chemistry (IUPAC). The cylinder is designed to encompass seven periodic periods, with elements distributed throughout based on their atomic order. This design allows for six vertical columns on the surface of the cylinder to represent the distribution of elements.

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