Extended periodic table - wikipedia Extended periodic table Extended periodic table Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury ( element ) Thallium Lead Bismuth Polonium Astatine Radon Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson Ununennium Unbinilium Unbiunium Unquadquadium Unquadpentium Unquadhexium Unquadseptium Unquadoctium Unquadennium Unpentnilium Unpentunium Unpentbium Unpenttrium Unpentquadium Unpentpentium Unpenthexium Unpentseptium Unpentoctium Unpentennium Unhexnilium Unhexunium Unhexbium Unhextrium Unhexquadium Unhexpentium Unhexhexium Unhexseptium Unhexoctium Unhexennium Unseptnilium Unseptunium Unseptbium Unbibium Unbitrium Unbiquadium Unbipentium Unbihexium Unbiseptium Unbioctium Unbiennium Untrinilium Untriunium Untribium Untritrium Untriquadium Untripentium Untrihexium Untriseptium Untrioctium Untriennium Unquadnilium Unquadunium Unquadbium Unquadtrium Element 119 in period 8 ( row 8 ; highlighted ) marks the start of theorizations Part of a series on the Periodic table Periodic table forms 18 - column large cells 32 - column ( large cells ) Alternative forms Chemical Galaxy Janet 's left step Beyond period 7 Fricke large cells Pyykkö Periodic table history Dmitri Mendeleev predictions Discovery of elements Naming & etymology for places for scientists controversies ( in East Asia ) Systematic element names Sets of elements By periodic table structure Groups ( 1 -- 18 ) 1 ( alkali metals ) 2 ( alkaline earth metals ) 5 6 7 8 9 10 11 12 13 14 15 ( pnictogens ) 16 ( chalcogens ) 17 ( halogens ) 18 ( noble gases ) Periods ( 1 -- 7... ) 5 6 7 8 + Aufbau Fricke Pyykkö Blocks ( s, p, d, f,... ) Atomic orbitals Aufbau principle By metallic classification Metals alkali alkaline earth transition post-transition lanthanide actinide ( super - / eka - super - ) Metalloids dividing metals & nonmetals Nonmetals polyatomic diatomic monatomic ( noble gas ) By other characteristics Coinage metals Platinum - group metals Precious metals Refractory metals Heavy metals Light metals Native metals Noble metals Main - group elements Rare - earth elements Transuranium, transplutonium elements Major, minor & trans - actinides Elements List of chemical elements... by abundance ( in human body ) by atomic properties by isotope stability by annual production by symbol Properties of elements Atomic weight Crystal structure Electron affinity configuration Electronegativity ( ( Allen ) ) ( ( Pauling ) ) Goldschmidt classification Nutrition Valence Data pages for elements Abundance Atomic radius Boiling point Critical point Density Elasticity Electrical resistivity Electron affinity / configuration Electronegativity Hardness Heat capacity / of fusion / of vaporization Ionization energy Melting point Oxidation state Speed of sound Thermal conductivity / expansion coefficient Vapor pressure Book Category Chemistry Portal An extended periodic table theorizes about elements beyond oganesson ( beyond period 7, or row 7 ). Currently seven periods in the periodic table of chemical elements are known and proven, culminating with atomic number 118, which completes the seventh row. If further elements with higher atomic numbers than this are discovered, they will be placed in additional periods, laid out ( as with the existing periods ) to illustrate periodically recurring trends in the properties of the elements concerned. Any additional periods are expected to contain a larger number of elements than the seventh period, as they are calculated to have an additional so - called g - block, containing at least 18 elements with partially filled g - orbitals in each period. An eight - period table containing this block was suggested by Glenn T. Seaborg in 1969. IUPAC defines an element to exist if its lifetime is longer than 10 seconds, which is the time it takes for the nucleus to form an electron cloud. No elements in this region have been synthesized or discovered in nature. The first element of the g - block may have atomic number 121, and thus would have the systematic name unbiunium. Elements in this region are likely to be highly unstable with respect to radioactive decay, and have extremely short half lives, although element 126 is hypothesized to be within an island of stability that is resistant to fission but not to alpha decay. It is not clear how many elements beyond the expected island of stability are physically possible, whether period 8 is complete, or if there is a period 9. According to the orbital approximation in quantum mechanical descriptions of atomic structure, the g - block would correspond to elements with partially filled g - orbitals, but spin - orbit coupling effects reduce the validity of the orbital approximation substantially for elements of high atomic number. While Seaborg 's version of the extended period had the heavier elements following the pattern set by lighter elements, as it did not take into account relativistic effects, models that take relativistic effects into account do not. Pekka Pyykkö and Burkhard Fricke used computer modeling to calculate the positions of elements up to Z = 172, and found that several were displaced from the Madelung rule. Richard Feynman noted that a simplistic interpretation of the relativistic Dirac equation runs into problems with electron orbitals at Z > 1 / α ≈ 137 as described in the sections below, suggesting that neutral atoms can not exist beyond element 137, and that a periodic table of elements based on electron orbitals therefore breaks down at this point. On the other hand, a more rigorous analysis calculates the limit to be Z ≈ 173. Contents 1 History 2 Predicted properties of eighth - period elements 2.1 Chemical and physical properties 2.1. 1 8s elements 2.1. 2 Superactinides 2.1. 3 7d transition metals 2.1. 4 Elements 167 to 172 2.1. 5 Beyond element 172 2.2 End of the periodic table 2.2. 1 Feynmanium and elements above the atomic number 137 2.2. 1.1 Bohr model 2.2. 1.2 Relativistic Dirac equation 2.3 Nuclear properties 2.4 Electron configurations 3 Attempts to synthesize still undiscovered elements 3.1 Ununennium 3.2 Unbinilium 3.3 Unbibium 3.4 Unbiquadium 3.5 Unbihexium 3.6 Unbiseptium 4 Possible natural occurrence 5 Extended periodic table 6 See also 7 References 8 Further reading 9 External links History It is unknown how far the periodic table might extend beyond the known 118 elements. Glenn T. Seaborg suggested that the highest possible element may be under Z = 130, while Walter Greiner predicted that there may not be a highest possible element. The table below shows one possibility for the appearance of the eighth period, with placement of elements primarily based on their predicted chemistry. Extended periodic table ( Large version ) v t e 5 6 7 8 9 10 11 12 13 14 15 16 17 18 He Li Be O Ne Na Mg Al Si Cl Ar Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 5 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te Xe 6 Cs Ba La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Hf Ta Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn 7 Fr Ra Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og 8 119 120 121 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 ‍ ‍ 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 ‍ Alkali metal Alkaline earth metal Superactinide Lanthanide Actinide Transition metal Post - ​ transition metal Metalloid Polyatomic nonmetal Diatomic nonmetal Noble gas predicted predicted predicted predicted predicted predicted predicted predicted predicted All of these hypothetical undiscovered elements are named by the International Union of Pure and Applied Chemistry ( IUPAC ) systematic element name standard which creates a generic name for use until the element has been discovered, confirmed, and an official name approved. These names are typically not used in the literature, and are referred to by their atomic numbers ; hence, element 164 would usually not be called `` unhexquadium '' ( the IUPAC systematic name ), but rather `` element 164 '' with symbol `` 164 '', `` ( 164 ) '', or `` E164 ''. As of April 2011, synthesis has been attempted for only ununennium, unbinilium, unbibium, unbiquadium, unbihexium, and unbiseptium. ( Z = 119, 120, 122, 124, 126, and 127 ) At element 118, the orbitals 1s, 2s, 2p, 3s, 3p, 3d, 4s, 4p, 4d, 4f, 5s, 5p, 5d, 5f, 6s, 6p, 6d, 7s and 7p are assumed to be filled, with the remaining orbitals unfilled. A simple extrapolation from the Aufbau principle would predict the eighth row to fill orbitals in the order 8s, 5g, 6f, 7d, 8p ; but after element 120, the proximity of the electron shells makes placement in a simple table problematic. Although a simple extrapolation of the periodic table, following Seaborg 's original concept, would put the elements after 120 as follows : 121 - 138 form the g - block superactinides ; 139 - 152 form the f - block superactinides, 153 - 161 would be transition metals ; 162 - 166 post-transition metals ; 167 = halogen ; 168 = noble gas ; 169 = alkali metal ; 170 = alkaline earth metal, Dirac - Fock calculations predict that it will most likely go : 121 - 142 form the g - block superactinides ; 143 - 156 form the f - block superactinides ; 157 - 165 form the transition metals ; 166 - 170 post-transition metals ; 171 = halogen ; 172 = noble gas. This article needs attention from an expert on the subject. Please add a reason or a talk parameter to this template to explain the issue with the article. Consider associating this request with a WikiProject. ( December 2011 ) Not all models show the higher elements following the pattern established by lighter elements. Pekka Pyykkö, for example, used computer modeling to calculate the positions of elements up to Z = 172, and found that several were displaced from the Madelung energy - ordering rule. He predicts that the orbital shells will fill up in this order : 8s, 5g, the first two spaces of 8p, 6f, 7d, 9s, the first two spaces of 9p, the rest of 8p. He also suggests that period 8 be split into three parts : 8a, containing 8s, 8b, containing the first two elements of 8p, 8c, containing 7d and the rest of 8p. Fricke et al. also predicted the extended periodic table up to 184. This model has been more widely used among scientists and is shown above as the main form of the extended periodic table. Predicted properties of eighth - period elements Element 118, oganesson, is the last element that has been synthesized. The next two elements, elements 119 and 120, should form an 8s series and be an alkali and alkaline earth metal respectively. Beyond element 120, the superactinide series is expected to begin, when the 8s electrons and the filling 8p, 7d, 6f, and 5g subshells determine the chemistry of these elements. Complete and accurate CCSD calculations are not available for elements beyond 122 because of the extreme complexity of the situation : the 5g, 6f, and 7d orbitals should have about the same energy level, and in the region of element 160 the 9s, 8p, and 9p orbitals should also be about equal in energy. This will cause the electron shells to mix so that the block concept no longer applies very well, and will also result in novel chemical properties that will make positioning these elements in a periodic table very difficult. For example, element 164 is expected to mix characteristics of the elements of group 10, 12, 14, and 18. Chemical and Physical properties 8s elements Main articles : Ununennium and Unbinilium Some predicted properties of elements 119 and 120 Property 119 120 Standard atomic weight ( 322 ) ( 325 ) Group Valence electron configuration 8s 8s Stable oxidation states 1, 3 2, 4 First ionization energy 437.1 kJ / mol 578.9 kJ / mol Metallic radius 260 pm 200 pm Density 3 g / cm 7 g / cm Melting point 0 -- 30 ° C 680 ° C Boiling point 630 ° C 1700 ° C The first two elements of period 8 are expected to be ununennium and unbinilium, elements 119 and 120. Their electron configurations should have the 8s orbital being filled. This orbital is relativistically stabilized and contracted and thus, elements 119 and 120 should be more like rubidium and strontium than their immediate neighbours above, francium and radium. Another effect of the relativistic contraction of the 8s orbital is that the atomic radii of these two elements should be about the same of those of francium and radium. They should behave like normal alkali and alkaline earth metals, normally forming + 1 and + 2 oxidation states respectively, but the relativistic destabilization of the 7p subshell and the relatively low ionization energies of the 7p electrons should make higher oxidation states like + 3 and + 4 ( respectively ) possible as well. Superactinides The superactinide series is expected to contain elements 121 to 157. In the superactinide series, the 7d, 8p, 6f and 5g shells should all fill simultaneously : this creates very complicated situations, so much so that complete and accurate CCSD calculations have been done only for elements 121 and 122. The first superactinide, unbiunium ( element 121 ), should be a congener of lanthanum and actinium and should have similar properties to them : its main oxidation state should be + 3, although the closeness of the valence subshells ' energy levels may permit higher oxidation states, just as in elements 119 and 120. Relativistic stabilization of the 8p subshell should result in a ground - state 8s 8p valence electron configuration for element 121, in contrast to the ds configurations of lanthanum and actinium. Its first ionization energy is predicted to be 429.4 kJ / mol, which would be lower than those of all known elements except for the alkali metals potassium, rubidium, caesium, and francium : this value is even lower than that of the period 8 alkali metal ununennium ( 463.1 kJ / mol ). Similarly, the next superactinide, unbibium ( element 122 ), may be a congener of cerium and thorium, with a main oxidation state of + 4, but would have a ground - state 7d 8s 8p valence electron configuration, unlike thorium 's 6d 7s configuration. Hence, its first ionization energy would be smaller than thorium 's ( Th : 6.3 eV ; Ubb : 5.6 eV ) because of the greater ease of ionizing unbibium 's 8p electron than thorium 's 6d electron. In the first few superactinides, the binding energies of the added electrons are predicted to be small enough that they can lose all their valence electrons ; for example, unbihexium ( element 126 ) could easily form a + 8 oxidation state, and even higher oxidation states for the next few elements may be possible. Unbihexium is also predicted to display a variety of other oxidation states : recent calculations have suggested a stable monofluoride UbhF may be possible, resulting from a bonding interaction between the 5g orbital on unbihexium and the 2 p orbital on fluorine. Other predicted oxidation states include + 2, + 4, and + 6 ; + 4 is expected to be the most usual oxidation state of unbihexium. The presence of electrons in g - orbitals, which do not exist in the ground state electron configuration of any currently known element, should allow presently unknown hybrid orbitals to form and influence the chemistry of the superactinides in new ways, although the absence of g electrons in known elements makes predicting their chemistry more difficult. Some predicted compounds of the superactinides ( X = a halogen ) 121 122 123 124 125 126 132 142 143 144 145 146 148 153 154 155 156 157 Compound UbuX UbbX UbtX UbqX UbpX UbpO 2 + UbhF UbhF UbhO UqbX UqbX UqtF UqqX UqqO 2 + UqqF UqqO UqpF UqoO Analogs La X Ac X Ce X Th X Np O2 + ThF UF UO 2 + Pu F PuO UO Oxidation states 5 6 6 1, 2, 4, 6, 8 6 4, 6 6, 8 3, 4, 5, 6, 8 6 8 12 0, 2 3, 5 In the later superactinides, the oxidation states should become lower. By element 132, the predominant most stable oxidation state will be only + 6 ; this is further reduced to + 3 and + 4 by element 144, and at the end of the superactinide series it will be only + 2 ( and possibly even 0 ) because the 6f shell, which is being filled at that point, is deep inside the electron cloud and the 8s and 8p electrons are bound too strongly to be chemically active. The 5g shell should be filled at element 144 and the 6f shell at around element 154, and at this region of the superactinides the 8p electrons are bound so strongly that they are no longer active chemically, so that only a few electrons can participate in chemical reactions. Calculations by Fricke et al. predict that at element 154, the 6f shell is full and there are no d - or other electron wave functions outside the chemically inactive 8s and 8p shells. This would cause element 154 to be very unreactive, so that it may exhibit properties similar to those of the noble gases. Similarly to the lanthanide and actinide contractions, there should be a superactinide contraction in the superactinide series where the ionic radii of the superactinides are smaller than expected. In the lanthanides, the contraction is about 4.4 pm per element ; in the actinides, it is about 3 pm per element. The contraction is larger in the lanthanides than in the actinides due to the greater localization of the 4f wave function as compared to the 5f wave function. Comparisons with the wave functions of the outer electrons of the lanthanides, actinides, and superactinides lead to a prediction of a contraction of about 2 pm per element in the superactinides ; although this is smaller than the contractions in the lanthanides and actinides, its total effect is larger due to the fact that 32 electrons are filled in the deeply buried 5g and 6f shells, instead of just 14 electrons being filled in the 4f and 5f shells in the lanthanides and actinides respectively. Pekka Pyykkö divides these superactinides into three series : a 5g series ( elements 121 to 138 ), an 8p series ( elements 139 to 140 ), and a 6f series ( elements 141 to 155 ), although noting that there would be a great deal of overlapping between energy levels and that the 6f, 7d, or 8p orbitals could well also be occupied in the early superactinide atoms or ions. He also expects that they would behave more like `` super lanthanides '', in the sense that the 5g electrons would mostly be chemically inactive, similarly to how only one or two 4f electrons in each lanthanide are ever ionized in chemical compounds. He also predicted that the possible oxidation states of the superactinides might rise very high in the 6f series, to values such as + 12 in element 148. As an example from the late superactinides, element 156 is expected to exhibit mainly the + 2 oxidation state. Its first ionization energy should be about 395.6 kJ / mol and its metallic radius should be about 170 picometers. It should be a very heavy metal with a density of around 26 g / cm. Its relative atomic mass should be around 445 u. 7d transition metals The transition metals in period 8 are expected to be elements 157 to 165 ; to these element 166 may be added to complete the 7d subshell. Although the 8s and 8p electrons are bound so strongly in these elements that they should not be able to take part in any chemical reactions, the 9s and 9p levels are expected to be readily available for hybridization such that these elements will still behave chemically like their lighter homologues in the periodic table, showing the same oxidation states as they do, in contrast to earlier predictions which predicted the period 8 transition metals to have main oxidation states two less than those of their lighter congeners. The noble metals of this series of transition metals are not expected to be as noble as their lighter homologues, due to the absence of an outer s shell for shielding and also because the 7d shell is strongly split into two subshells due to relativistic effects. This causes the first ionization energies of the 7d transition metals to be smaller than those of their lighter congeners. Calculations predict that the 7d electrons of element 164 ( unhexquadium ) should participate very readily in chemical reactions, so that unhexquadium should be able to show stable + 6 and + 4 oxidation states in addition to the normal + 2 state in aqueous solutions with strong ligands. Unhexquadium should thus be able to form compounds like Uhq ( CO ), Uhq ( PF ) ( both tetrahedral ), and Uhq ( CN ) 2 − 2 ( linear ), which is very different behavior from that of lead, which unhexquadium would be a heavier homologue of if not for relativistic effects. Nevertheless, the divalent state would be the main one in aqueous solution, and unhexquadium ( II ) should behave more similarly to lead than unhexquadium ( IV ) and unhexquadium ( VI ). Unhexquadium should be a soft metal like mercury, and metallic unhexquadium should have a high melting point as it is predicted to bond covalently. It is also expected to be a soft Lewis acid and have Ahrlands softness parameter close to 4 eV. It should also have some similarities to oganesson as well as to the other group 12 elements. Unhexquadium should be at most moderately reactive, having a first ionization energy that should be around 685 kJ / mol, comparable to that of molybdenum. Due to the lanthanide, actinide, and superactinide contractions, unhexquadium should have a metallic radius of only 158 pm, very close to that of the much lighter magnesium, despite its being expected to have an atomic weight of around 474 u, about 19.5 times as much as that of magnesium. This small radius and high weight cause it to be expected to have an extremely high density of around 46 g cm, over twice that of osmium, currently the most dense element known, at 22.61 g cm ; unhexquadium should be the second most dense element in the first 172 elements in the periodic table, with only its neighbor unhextrium ( element 163 ) being more dense ( at 47 g cm ). Metallic unhexquadium should be quite stable, as the 8s and 8p electrons are very deeply buried in the electron core and only the 7d electrons are available for bonding. Metallic unhexquadium should have a very large cohesive energy ( enthalpy of crystallization ) due to its covalent bonds, most probably resulting in a high melting point. Theoretical interest in the chemistry of unhexquadium is largely motivated by theoretical predictions that it, especially the isotope Uhq ( with 164 protons and 318 neutrons ), would be at the center of a hypothetical second island of stability ( the first being centered on copernicium, particularly the isotopes Cn, Cn, and Cn which are expected to have half - lives of centuries or millennia ). Elements 165 ( unhexpentium ) and 166 ( unhexhexium ), the last two 7d metals, should behave similarly to alkali and alkaline earth metals when in the + 1 and + 2 oxidation states respectively. The 9s electrons should have ionization energies comparable to those of the 3s electrons of sodium and magnesium, due to relativistic effects causing the 9s electrons to be much more strongly bound than non-relativistic calculations would predict. Elements 165 and 166 should normally exhibit the + 1 and + 2 oxidation states respectively, although the ionization energies of the 7d electrons are low enough to allow higher oxidation states like + 3 for element 165. The oxidation state + 4 for element 166 is less likely, creating a situation similar to the lighter elements in groups 11 and 12 ( particularly gold and mercury ). Some predicted properties of the 7d transition metals. The metallic radii and densities are first approximations. X represents a halogen. Most analogous group is given first, followed by other similar groups. Property 157 158 159 160 161 162 163 164 165 166 Standard atomic weight ( 448 ) ( 452 ) ( 456 ) ( 459 ) ( 463 ) ( 466 ) ( 470 ) ( 474 ) ( 477 ) ( 481 ) Group ( 5 ) ( 6 ) 5 ( 7 ) 6 ( 8 ) 7 ( 9 ) 8 ( 10 ) 9 ( 11 ) 10 ( 12, 14, 18 ) 11 ( 1, 13 ) 12 ( 2, 14 ) Valence electron configuration 7d 7d 7d 9s 7d 9s 7d 9s 7d 9s 7d 9s 7d 7d 9s 7d 9s Stable oxidation states 5 2, 4, 6 1, 3 First ionization energy 453.5 kJ / mol 521.0 kJ / mol 337.7 kJ / mol 424.5 kJ / mol 472.8 kJ / mol 559.6 kJ / mol 617.5 kJ / mol 685.0 kJ / mol 521.0 kJ / mol 627.2 kJ / mol Metallic radius 163 pm 157 pm 152 pm 148 pm 148 pm 149 pm 152 pm 158 pm 250 pm 200 pm Density 28 g / cm 30 g / cm 33 g / cm 36 g / cm 40 g / cm 45 g / cm 47 g / cm 46 g / cm 7 g / cm 11 g / cm Elements 167 to 172 The next six elements on the periodic table should be the last six main - group elements before the end of the periodic table at Z = 173. In elements 167 to 172, the 9p and 8p shells will be filled. Their energy eigenvalues are so close together that they behave as one combined p shell, similar to the non-relativistic 2p and 3p shells. Thus, the inert pair effect does not occur and the most common oxidation states of elements 167 to 170 should be + 3, + 4, + 5, and + 6 respectively. Element 171 ( unseptunium ) is expected to show some similarities to the halogens, showing various oxidation states ranging from − 1 to + 7, although its physical properties should be closer to that of a metal. Its electron affinity should be 3.0 eV, allowing it to form HUsu, analogous to a hydrogen halide. The Usu ion is expected to be a soft base, comparable to iodide ( I ). Element 172 ( unseptbium ) should be a noble gas with chemical behaviour similar to that of xenon, as their ionization energies should be very similar ( Xe, 1170.4 kJ / mol ; Usb, 1090.3 kJ / mol ). The only main difference between them is that element 172, unlike xenon, is expected to be a liquid or a solid at standard temperature and pressure due to its much higher atomic weight. Unseptbium should be a strong Lewis acid, forming fluorides and oxides, similarly to its lighter congener xenon. Because of this analogy of elements 165 -- 172 to periods 2 and 3, Fricke et al. considered them to form a ninth period of the periodic table, while the eighth period was taken by them to end at the noble metal element 164. This ninth and final period would be similar to the second and third period in that it should have no transition metals. Some predicted properties of elements 167 -- 172, the last main - group elements on the periodic table. The metallic or covalent radii and densities are first approximations. Most analogous group is given first, followed by other similar groups. Property 167 168 169 170 171 172 Standard atomic weight ( 485 ) ( 489 ) ( 493 ) ( 496 ) ( 500 ) ( 504 ) Group 13 14 15 16 17 18 Valence electron configuration 9s 9p 9s 9p 9s 9p 8p 9s 9p 8p 9s 9p 8p 9s 9p 8p Stable oxidation states 5 6 − 1, 3, 7 0, 4, 6, 8 First ionization energy 617.5 kJ / mol 723.6 kJ / mol 800.8 kJ / mol 887.7 kJ / mol 984.2 kJ / mol 1090.3 kJ / mol Metallic or covalent radius 190 pm 180 pm 175 pm 170 pm 165 pm 220 pm Density 17 g / cm 19 g / cm 18 g / cm 17 g / cm 16 g / cm 9 g / cm Beyond element 172 Immediately after element 172 ( unseptbium, the last period 8 element ), the first noble gas after oganesson ( the last period 7 element ), it was originally expected that another long transition series like the superactinides should begin, filling the 6g, 7f, 8d, and perhaps 6h shells. These electrons would be very loosely bound, rendering extremely high oxidation states possibly easy to reach. Element 184 ( unoctquadium ) was significantly targeted in early predictions, as it was originally speculated that 184 would be a proton magic number. However, these extrapolations are unlikely to be fulfilled, due to the impending end of the periodic table at Z = 173. In element 173 ( unsepttrium ), the last electron would enter the 6g subshell. End of the periodic table The number of physically possible elements is unknown. A low estimate is that the periodic table may end soon after the island of stability, which is expected to center on Z = 126, as the extension of the periodic and nuclides tables is restricted by the proton and the neutron drip lines ; some, such as Walter Greiner, predicted that there may not be an end to the periodic table. Other predictions of an end to the periodic table include Z = 128 ( John Emsley ) and Z = 155 ( Albert Khazan ). Feynmanium and elements above the atomic number 137 It is a `` folk legend '' among physicists that Richard Feynman suggested that neutral atoms could not exist for atomic numbers greater than Z = 137, on the grounds that the relativistic Dirac equation predicts that the ground - state energy of the innermost electron in such an atom would be an imaginary number. Here, the number 137 arises as the inverse of the fine - structure constant. By this argument, neutral atoms can not exist beyond untriseptium ( alternatively called `` feynmanium '' ), and therefore a periodic table of elements based on electron orbitals breaks down at this point. However, this argument presumes that the atomic nucleus is pointlike. A more accurate calculation must take into account the small, but nonzero, size of the nucleus, which is predicted to push the limit further to Z ≈ 173. Bohr model The Bohr model exhibits difficulty for atoms with atomic number greater than 137, for the speed of an electron in a 1s electron orbital, v, is given by v = Z α c ≈ Z c 137.036 ( displaystyle v = Z alpha c approx ( \frac ( Zc ) ( 137.036 ) ) ) where Z is the atomic number, and α is the fine structure constant, a measure of the strength of electromagnetic interactions. Under this approximation, any element with an atomic number of greater than 137 would require 1s electrons to be traveling faster than c, the speed of light. Hence the non-relativistic Bohr model is clearly inaccurate when applied to such an element. Relativistic Dirac equation The relativistic Dirac equation gives the ground state energy as E = m c 2 1 + Z 2 α 2 n − ( j + 1 2 ) + ( j + 1 2 ) 2 − Z 2 α 2, ( displaystyle E = ( \frac ( mc ^ ( 2 ) ) ( sqrt ( 1 + ( dfrac ( Z ^ ( 2 ) alpha ^ ( 2 ) ) ( n - left ( j+ ( \frac ( 1 ) ( 2 ) ) \right ) + ( sqrt ( left ( j+ ( \frac ( 1 ) ( 2 ) ) \right ) ^ ( 2 ) - Z ^ ( 2 ) alpha ^ ( 2 ) ) ) ) ) ) ) ), ) where m is the rest mass of the electron. For Z > 137, the wave function of the Dirac ground state is oscillatory, rather than bound, and there is no gap between the positive and negative energy spectra, as in the Klein paradox. More accurate calculations taking into account the effects of the finite size of the nucleus indicate that the binding energy first exceeds 2mc for Z > Z ≈ 173. For Z > Z, if the innermost orbital ( 1s ) is not filled, the electric field of the nucleus will pull an electron out of the vacuum, resulting in the spontaneous emission of a positron. The precise details of what happens to atoms with Z > 173 are not known yet, but they probably should not survive long enough as such to be considered elements. Nuclear properties The first island of stability is expected to be centered on unbibium - 306 ( with 122 protons and 184 neutrons ), and the second is expected to be centered on unhexquadium - 482 ( with 164 protons and 318 neutrons ). This second island of stability should confer additional stability on elements 152 -- 168 ; on the other hand, due to the enormously greater forces of electromagnetic repulsion that must be overcome by the strong force at this second island, it is possible that nuclei around this region only exist as resonances and can not stay together for a meaningful amount of time. It is also possible that some of the superactinides between these series may not actually exist because they are too far from both islands, in which case the periodic table would quite possibly end around Z = 130 instead of 173, with nuclear properties imposing an end earlier than the electronic properties. Calculations according to the Hartree -- Fock -- Bogoliubov Method using the non-relativistic Skyrme interaction have proposed Z = 126 as a closed proton shell. In this region of the periodic table, N = 184 and N = 196 have been suggested as closed neutron shells. Therefore, the isotopes of most interest are Ubh and Ubh, for these might be considerably longer - lived than other isotopes. Element 126, having a magic number of protons, is predicted to be more stable than other elements in this region, and may have nuclear isomers with very long half - lives. Electron configurations The following are the expected electron configurations of elements 118 -- 173. Beyond element 122, no complete calculations are available and hence the data in this table must be taken as tentative. Chemical element Chemical series Predicted electron configuration 118 Og Oganesson Noble gas ( Rn ) 5f 6d 7s 7p 119 Uue Ununennium Alkali metal ( Og ) 8s 120 Ubn Unbinilium Alkaline earth metal ( Og ) 8s 121 Ubu Unbiunium Superactinide ( Og ) 8s 8p 1 1 / 2 122 Ubb Unbibium Superactinide ( Og ) 7d 8s 8p 1 1 / 2 123 Ubt Unbitrium Superactinide ( Og ) 6f 8s 8p 1 1 / 2 124 Ubq Unbiquadium Superactinide ( Og ) 6f 8s 8p 1 1 / 2 125 Ubp Unbipentium Superactinide ( Og ) 5g 6f 8s 8p 2 1 / 2 126 Ubh Unbihexium Superactinide ( Og ) 5g 6f 8s 8p 1 1 / 2 127 Ubs Unbiseptium Superactinide ( Og ) 5g 6f 8s 8p 2 1 / 2 128 Ubo Unbioctium Superactinide ( Og ) 5g 6f 8s 8p 2 1 / 2 129 Ube Unbiennium Superactinide ( Og ) 5g 6f 7d 8s 8p 1 1 / 2 130 Utn Untrinilium Superactinide ( Og ) 5g 6f 7d 8s 8p 1 1 / 2 131 Utu Untriunium Superactinide ( Og ) 5g 6f 8s 8p 2 1 / 2 132 Utb Untribium Superactinide ( Og ) 5g 6f 8s 8p 2 1 / 2 133 Utt Untritrium Superactinide ( Og ) 5g 6f 8s 8p 2 1 / 2 134 Utq Untriquadium Superactinide ( Og ) 5g 6f 8s 8p 2 1 / 2 135 Utp Untripentium Superactinide ( Og ) 5g 6f 8s 8p 2 1 / 2 136 Uth Untrihexium Superactinide ( Og ) 5g 6f 8s 8p 2 1 / 2 137 Uts Untriseptium Superactinide ( Og ) 5g 6f 8s 8p 2 1 / 2 138 Uto Untrioctium Superactinide ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 139 Ute Untriennium Superactinide ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 140 Uqn Unquadnilium Superactinide ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 141 Uqu Unquadunium Superactinide ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 142 Uqb Unquadbium Superactinide ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 143 Uqt Unquadtrium Superactinide ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 144 Uqq Unquadquadium Superactinide ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 145 Uqp Unquadpentium Superactinide ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 146 Uqh Unquadhexium Superactinide ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 147 Uqs Unquadseptium Superactinide ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 148 Uqo Unquadoctium Superactinide ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 149 Uqe Unquadennium Superactinide ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 150 Upn Unpentnilium Superactinide ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 151 Upu Unpentunium Superactinide ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 152 Upb Unpentbium Superactinide ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 153 Upt Unpenttrium Superactinide ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 154 Upq Unpentquadium Superactinide ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 155 Upp Unpentpentium Superactinide ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 156 Uph Unpenthexium Superactinide ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 157 Ups Unpentseptium Superactinide ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 158 Upo Unpentoctium Transition metal ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 159 Upe Unpentennium Transition metal ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 9s 160 Uhn Unhexnilium Transition metal ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 9s 161 Uhu Unhexunium Transition metal ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 9s 162 Uhb Unhexbium Transition metal ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 9s 163 Uht Unhextrium Transition metal ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 9s 164 Uhq Unhexquadium Transition metal ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 165 Uhp Unhexpentium Transition metal ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 9s 166 Uhh Unhexhexium Post-transition metal ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 9s 167 Uhs Unhexseptium Post-transition metal ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 9s 9p 1 1 / 2 168 Uho Unhexoctium Post-transition metal ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 9s 9p 2 1 / 2 169 Uhe Unhexennium Post-transition metal ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 8p 1 3 / 2 9s 9p 2 1 / 2 170 Usn Unseptnilium Post-transition metal ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 8p 2 3 / 2 9s 9p 2 1 / 2 171 Usu Unseptunium Post-transition metal ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 8p 3 3 / 2 9s 9p 2 1 / 2 172 Usb Unseptbium Noble gas ( Og ) 5g 6f 7d 8s 8p 2 1 / 2 8p 4 3 / 2 9s 9p 2 1 / 2 173 Ust Unsepttrium -- ( Usb ) 6g Attempts to synthesize still undiscovered elements Projects to build period 8 elements that have had synthesis attempts were elements 119, 120, 122, 124, 126, and 127. So far, none of these synthesis attempts were successful. Ununennium The synthesis of ununennium was first attempted in 1985 by bombarding a target of einsteinium - 254 with calcium - 48 ions at the superHILAC accelerator at Berkeley, California : 254 99 Es + 48 20 Ca → 302 119 Uue * → no atoms No atoms were identified, leading to a limiting cross section of 300 nb. Later calculations suggest that the cross section of the 3n reaction ( which would result in Uue and three neutrons as products ) would actually be six hundred thousand times lower than this upper bound, at 0.5 pb. As ununennium is the lightest undiscovered element, it has been the target of synthesis experiments by both German and Russian teams in recent years. The Russian experiments were conducted in 2011, and no results were released, strongly implying that no ununennium atoms were identified. From April to September 2012, an attempt to synthesize the isotopes Uue and Uue was made by bombarding a target of berkelium - 249 with titanium - 50 at the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt, Germany. Based on the theoretically predicted cross-section, it was expected that an ununennium atom would be synthesized within five months of the beginning of the experiment. 249 97 Bk + 50 22 Ti → 299 119 Uue * → 296 119 Uue + 3 1 0 n 249 97 Bk + 50 22 Ti → 299 119 Uue * → 295 119 Uue + 4 1 0 n The experiment was originally planned to continue to November 2012, but was stopped early to make use of the Bk target to confirm the synthesis of tennessine ( thus changing the projectiles to Ca ). This reaction between Bk and Ti was predicted to be the most favorable practical reaction for formation of ununennium, as it is rather asymmetrical, though also somewhat cold. ( The reaction between Es and Ca would be superior, but preparing milligram quantities of Es for a target is difficult. ) Nevertheless, the necessary change from the `` silver bullet '' Ca to Ti divides the expected yield of ununennium by about twenty, as the yield is strongly dependent on the asymmetry of the fusion reaction. Due to the predicted short half - lives, the GSI team used new `` fast '' electronics capable of registering decay events within microseconds. No ununennium atoms were identified, implying a limiting cross-section of 70 fb. The predicted actual cross-section is around 40 fb, which is at the limits of current technology. The team at the Joint Institute for Nuclear Research in Dubna, Russia, is planning to begin new experiments on the synthesis of ununennium and unbinilium using the Bk+ Ti and Cf+ Ti reactions in 2019 using a new experimental complex. The team at RIKEN in Japan also plans to make attempts on these elements around the same time with Cm targets using the Cm+ V and Cm+ Cr reactions. Unbinilium Following their success in obtaining oganesson by the reaction between Cf and Ca in 2006, the team at the Joint Institute for Nuclear Research ( JINR ) in Dubna started similar experiments in hope of creating unbinilium ( element 120 ) from nuclei of Fe and Pu. Isotopes of unbinilium are predicted to have alpha decay half - lives of the order of microseconds. In March -- April 2007, the synthesis of unbinilium was attempted at the JINR by bombarding a plutonium - 244 target with iron - 58 ions. Initial analysis revealed that no atoms of element 120 were produced providing a limit of 400 fb for the cross section at the energy studied. 244 94 Pu + 58 26 Fe → 302 120 Ubn * → no atoms The Russian team planned to upgrade their facilities before attempting the reaction again. In April 2007, the team at the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt, Germany attempted to create unbinilium using uranium - 238 and nickel - 64 : 238 92 U + 64 28 Ni → 302 120 Ubn * → no atoms No atoms were detected providing a limit of 1.6 pb on the cross section at the energy provided. The GSI repeated the experiment with higher sensitivity in three separate runs from April -- May 2007, January -- March 2008, and September -- Oct 2008, all with negative results and providing a cross section limit of 90 fb. In June -- July 2010, and again in 2011, after upgrading their equipment to allow the use of more radioactive targets, scientists at the GSI attempted the more asymmetrical fusion reaction : 248 96 Cm + 54 24 Cr → 302 120 Ubn * → no atoms It was expected that the change in reaction would quintuple the probability of synthesizing unbinilium, as the yield of such reactions is strongly dependent on their asymmetry. Three correlated signals were observed that matched the predicted alpha decay energies of Ubn and its daughter Og, as well as the experimentally known decay energy of its granddaughter Lv. However, the lifetimes of these possible decays were much longer than expected, and the results could not be confirmed. In August -- October 2011, a different team at the GSI using the TASCA facility tried a new, even more asymmetrical reaction : 249 98 Cf + 50 22 Ti → 299 120 Ubn * → no atoms Because of its asymmetry, the reaction between Cf and Ti was predicted to be the most favorable practical reaction for synthesizing unbinilium, although it is also somewhat cold. No unbinilium atoms were identified, implying a limiting cross-section of 200 fb. Jens Volker Kratz predicted the actual maximum cross-section for producing unbinilium by any of these reactions to be around 0.1 fb ; in comparison, the world record for the smallest cross section of a successful reaction was 30 fb for the reaction Bi ( Zn, n ) Nh, and Kratz predicted a maximum cross-section of 20 fb for producing the neighbouring ununennium. If these predictions are accurate, then synthesizing ununennium would be at the limits of current technology, and synthesizing unbinilium would require new methods. The team at the Joint Institute for Nuclear Research in Dubna, Russia, is planning to begin new experiments on the synthesis of ununennium and unbinilium using the Bk+ Ti and Cf+ Ti reactions in 2019 using a new experimental complex. The team at RIKEN in Japan also plans to make attempts on these elements around the same time with Cm targets using the Cm+ V and Cm+ Cr reactions. Unbibium The first attempt to synthesize unbibium was performed in 1972 by Flerov et al. at JINR ( Joint Institute for Nuclear Research ), using the hot fusion reaction : 238 92 U + 66 30 Zn → 304 122 Ubb * → no atoms No atoms were detected and a yield limit of 5 mb ( 5,000,000,000 pb ) was measured. Current results ( see flerovium ) have shown that the sensitivity of this experiment was too low by at least 6 orders of magnitude. In 2000, the Gesellschaft für Schwerionenforschung ( GSI ) performed a very similar experiment with much higher sensitivity : 238 92 U + 70 30 Zn → 308 122 Ubb * → no atoms These results indicate that the synthesis of such heavier elements remains a significant challenge and further improvements of beam intensity and experimental efficiency is required. The sensitivity should be increased to 1 fb. Another unsuccessful attempt to synthesize unbibium was carried out in 1978 at the GSI, where a natural erbium target was bombarded with xenon - 136 ions : nat 68 Er + 136 54 Xe → 298,300,302,303,304,306 Ubb * → no atoms The two attempts in the 1970s to synthesize unbibium were caused by research investigating whether superheavy elements could potentially be naturally occurring. Several experiments have been performed between 2000 - 2004 at the Flerov laboratory of Nuclear Reactions studying the fission characteristics of the compound nucleus Ubb. Two nuclear reactions have been used, namely Cm + Fe and Pu + Ni. The results have revealed how nuclei such as this fission predominantly by expelling closed shell nuclei such as Sn ( Z = 50, N = 82 ). It was also found that the yield for the fusion - fission pathway was similar between Ca and Fe projectiles, indicating a possible future use of Fe projectiles in superheavy element formation. Unbiquadium In a series of experiments, scientists at GANIL ( Grand Accélérateur National d'Ions Lourds ) have attempted to measure the direct and delayed fission of compound nuclei of elements with Z = 114, 120, and 124 in order to probe shell effects in this region and to pinpoint the next spherical proton shell. This is because having complete nuclear shells ( or, equivalently, having a magic number of protons or neutrons ) would confer more stability on the nuclei of such superheavy elements, thus moving closer to the island of stability. In 2006, with full results published in 2008, the team provided results from a reaction involving the bombardment of a natural germanium target with uranium ions : 238 92 U + nat 32 Ge → 308,310,311,312,314 Ubq * → fission The team reported that they had been able to identify compound nuclei fissioning with half - lives > 10 s. This result suggests a strong stabilizing effect at Z = 124 and points to the next proton shell at Z > 120, not at Z = 114 as previously thought. A compound nucleus is a loose combination of nucleons that have not arranged themselves into nuclear shells yet. It has no internal structure and is held together only by the collision forces between the target and projectile nuclei. It is estimated that it requires around 10 s for the nucleons to arrange themselves into nuclear shells, at which point the compound nucleus becomes a nuclide, and this number is used by IUPAC as the minimum half - life a claimed isotope must have to potentially be recognised as being discovered. Thus, the GANIL experiments do not count as a discovery of element 124. Unbihexium The first and only attempt to synthesize unbihexium, which was unsuccessful, was performed in 1971 at CERN ( European Organization for Nuclear Research ) by René Bimbot and John M. Alexander using the hot fusion reaction : 232 90 Th + 84 36 Kr → 316 126 Ubh * → no atoms A high - energy alpha particle was observed and taken as possible evidence for the synthesis of unbihexium. Recent research suggests that this is highly unlikely as the sensitivity of experiments performed in 1971 would have been several orders of magnitude too low according to current understanding. Unbiseptium Unbiseptium has had one failed attempt at synthesis in 1978 at the Darmstadt UNILAC accelerator by bombarding a natural tantalum target with xenon ions : nat 73 Ta + 136 54 Xe → 316,317 Ubs * → no atoms Possible natural occurrence On April 24, 2008, a group led by Amnon Marinov at the Hebrew University of Jerusalem claimed to have found single atoms of unbibium - 292 in naturally occurring thorium deposits at an abundance of between 10 and 10, relative to thorium. The claim of Marinov et al. was criticized by a part of the scientific community, and Marinov says he has submitted the article to the journals Nature and Nature Physics but both turned it down without sending it for peer review. The unbibium - 292 atoms were claimed to be superdeformed or hyperdeformed isomers, with a half - life of at least 100 million years. A criticism of the technique, previously used in purportedly identifying lighter thorium isotopes by mass spectrometry, was published in Physical Review C in 2008. A rebuttal by the Marinov group was published in Physical Review C after the published comment. A repeat of the thorium - experiment using the superior method of Accelerator Mass Spectrometry ( AMS ) failed to confirm the results, despite a 100-fold better sensitivity. This result throws considerable doubt on the results of the Marinov collaboration with regard to their claims of long - lived isotopes of thorium, roentgenium and unbibium. It is still possible that traces of unbibium might only exist in some thorium samples, although this is unlikely. It was suggested in 1976 that primordial superheavy elements ( mainly livermorium, unbiquadium, unbihexium, and unbiseptium ) could be a cause of unexplained radiation damage in minerals. This prompted many researchers to search for them in nature from 1976 to 1983. Some claimed that they had detected alpha particles with the right energies to cause the damage observed, supporting the presence of these elements, while some claimed that none had been detected. The possible extent of primordial superheavy elements on Earth today is uncertain. Even if they are confirmed to have caused the radiation damage long ago, they might now have decayed to mere traces, or even be completely gone. Extended periodic table Extended periodic table Superheavy elements may not exist, and may not follow the order of this table even if they do exist. He Li Be 5 6 7 8 O 9 10 Ne 11 Na 12 Mg 13 Al 14 Si 15 16 17 Cl 18 Ar 19 20 Ca 21 Sc 22 Ti 23 V 24 Cr 25 Mn 26 Fe 27 Co 28 Ni 29 Cu 30 Zn 31 Ga 32 Ge 33 As 34 Se 35 Br 36 Kr 5 37 Rb 38 Sr 39 Y 40 Zr 41 Nb 42 Mo 43 Tc 44 Ru 45 Rh 46 Pd 47 Ag 48 Cd 49 In 50 Sn 51 Sb 52 Te 53 54 Xe 6 55 Cs 56 Ba 57 La 58 Ce 59 Pr 60 Nd 61 Pm 62 Sm 63 Eu 64 Gd 65 Tb 66 Dy 67 Ho 68 Er 69 Tm 70 Yb 71 Lu 72 Hf 73 Ta 74 75 Re 76 Os 77 Ir 78 Pt 79 Au 80 Hg 81 Tl 82 Pb 83 Bi 84 Po 85 At 86 Rn 7 87 Fr 88 Ra 89 Ac 90 Th 91 Pa 92 U 93 Np 94 Pu 95 Am 96 Cm 97 Bk 98 Cf 99 Es 100 Fm 101 Md 102 No 103 Lr 104 Rf 105 Db 106 Sg 107 Bh 108 Hs 109 Mt 110 Ds 111 Rg 112 Cn 113 Nh 114 Fl 115 Mc 116 Lv 117 Ts 118 Og 8 119 Uue 120 Ubn 121 Ubu 122 Ubb 123 Ubt 124 Ubq 125 Ubp 126 Ubh 127 Ubs 128 Ubo 129 Ube 130 Utn 131 Utu 132 Utb 133 Utt 134 Utq 135 Utp 136 Uth 137 Uts 138 Uto 139 Ute 140 Uqn 141 Uqu 142 Uqb 143 Uqt 144 Uqq 145 Uqp 146 Uqh 147 Uqs 148 Uqo 149 Uqe 150 Upn 151 Upu 152 Upb 153 Upt 154 Upq 155 Upp 156 Uph 157 Ups 158 Upo 159 Upe 160 Uhn 161 Uhu 162 Uhb 163 Uht 164 Uhq 165 Uhp 166 Uhh 167 Uhs 168 Uho Legend s - block p - block d - block f - block Background color shows the block of the periodic table s - block p - block d - block f - block g - block Predicted elements are colored in a lighter shade See also Table of nuclides ( combined ) Hypernucleus References Jump up ^ Seaborg, Glenn T. ( August 26, 1996 ). `` An Early History of LBNL ''. Jump up ^ Frazier, K. ( 1978 ). `` Superheavy Elements ''. Science News. 113 ( 15 ) : 236 -- 238. doi : 10.2307 / 3963006. JSTOR 3963006. Jump up ^ `` Kernchemie ''. Jump up ^ Element 122 was claimed to exist naturally in April 2008, but this claim was widely believed to be erroneous. `` Heaviest element claim criticised ''. Rsc.org. 2008 - 05 - 02. Retrieved 2010 - 03 - 16. ^ Jump up to : Fricke, B. ; Greiner, W. ; Waber, J.T. ( 1971 ). `` The continuation of the periodic table up to Z = 172. The chemistry of superheavy elements ''. Theoretica chimica acta. Springer - Verlag. 21 ( 3 ) : 235 -- 260. doi : 10.1007 / BF01172015. Retrieved 28 November 2012. ^ Jump up to : `` Extended elements : new periodic table ''. 2010. Jump up ^ Elert, G. `` Atomic Models ''. The Physics Hypertextbook. Retrieved 2009 - 10 - 09. ^ Jump up to : Seaborg, Glenn T. ( c. 2006 ). `` transuranium element ( chemical element ) ''. Encyclopædia Britannica. Retrieved 2010 - 03 - 16. ^ Jump up to : Philip Ball ( November 2010 ). `` Would element 137 really spell the end of the periodic table ? Philip Ball examines the evidence ''. Chemistry World. Royal Society of Chemistry. Retrieved 2012 - 09 - 30. ^ Jump up to : Pyykkö, Pekka ( 2011 ). `` A suggested periodic table up to Z ≤ 172, based on Dirac -- Fock calculations on atoms and ions ''. Physical Chemistry Chemical Physics. 13 ( 1 ) : 161 -- 8. Bibcode : 2011PCCP... 13... 161P. doi : 10.1039 / c0cp01575j. PMID 20967377. ^ Jump up to : Hoffman, Darleane C. ; Lee, Diana M. ; Pershina, Valeria ( 2006 ). `` Transactinides and the future elements ''. In Morss ; Edelstein, Norman M. ; Fuger, Jean. The Chemistry of the Actinide and Transactinide Elements ( 3rd ed. ). Dordrecht, The Netherlands : Springer Science + Business Media. ISBN 1 - 4020 - 3555 - 1. ^ Jump up to : Fricke, Burkhard ( 1975 ). `` Superheavy elements : a prediction of their chemical and physical properties ''. Recent Impact of Physics on Inorganic Chemistry. 21 : 89 -- 144. doi : 10.1007 / BFb0116498. Retrieved 4 October 2013. Jump up ^ Waber, J.T. ( 1969 ). `` SCF Dirac -- Slater Calculations of the Translawrencium Elements ''. The Journal of Chemical Physics. 51 ( 2 ) : 664. Bibcode : 1969JChPh... 51... 664W. doi : 10.1063 / 1.1672054. Jump up ^ Jacoby, Mitch ( 2006 ). `` As - yet - unsynthesized superheavy atom should form a stable diatomic molecule with fluorine ''. Chemical & Engineering News. 84 ( 10 ) : 19. doi : 10.1021 / cen - v084n010. p019a. Retrieved 2008 - 01 - 14. Jump up ^ Makhyoun, M.A. ( October 1988 ). `` On the electronic structure of 5g complexes of element 125 : a quasi-relativistic MS - Xα study ''. Journal de Chimie Physique et de Physico - Chimie Biologique. EDP Sciences, Les Ulis, FRANCE ( 1903 - 2000 ). 85 ( 10 ) : 917 -- 24. ^ Jump up to : Kratz, J.V. ( 5 September 2011 ). The Impact of Superheavy Elements on the Chemical and Physical Sciences ( PDF ). 4th International Conference on the Chemistry and Physics of the Transactinide Elements. Retrieved 27 August 2013. ^ Jump up to : `` Nuclear scientists eye future landfall on a second ' island of stability ' ''. EurekAlert !. 6 April 2008. ^ Jump up to : `` Investigation of the stability of superheavy nuclei aroundZ = 114 andZ = 164 ''. Zeitschrift für Physik. 228 : 371 -- 386. Bibcode : 1969ZPhy... 228... 371G. doi : 10.1007 / BF01406719. Jump up ^ Penneman, R.A. ; Mann, J.B. ; Jørgensen, C.K. ( February 1971 ). `` Speculations on the chemistry of superheavy elements such as Z = 164 ''. Chemical Physics Letters. 8 ( 4 ) : 321 -- 326. Bibcode : 1971CPL... 8... 321P. doi : 10.1016 / 0009 - 2614 ( 71 ) 80054 - 4. ^ Jump up to : Fricke, Burkhard ( 1977 ). `` Dirac - Fock - Slater calculations for the elements Z = 100, fermium, to Z = 173 '' ( PDF ). Recent Impact of Physics on Inorganic Chemistry. 19 : 83 -- 192. Bibcode : 1977ADNDT... 19... 83F. doi : 10.1016 / 0092 - 640X ( 77 ) 90010 - 9. Retrieved 25 February 2016. Jump up ^ Cwiok, S. ; Heenen, P. - H. ; Nazarewicz, W. ( 2005 ). `` Shape coexistence and triaxiality in the superheavy nuclei ''. Nature. 433 ( 7027 ) : 705 -- 9. Bibcode : 2005Natur. 433... 705C. doi : 10.1038 / nature03336. PMID 15716943. ^ Jump up to : Emsley, John ( 2011 ). Nature 's Building Blocks : An A-Z Guide to the Elements ( New ed. ). New York, NY : Oxford University Press. p. 588. ISBN 978 - 0 - 19 - 960563 - 7. Jump up ^ Eisberg, R. ; Resnick, R. ( 1985 ). Quantum Physics of Atoms, Molecules, Solids, Nuclei and Particles. Wiley. Jump up ^ Bjorken, J.D. ; Drell, S.D. ( 1964 ). Relativistic Quantum Mechanics. McGraw - Hill. Jump up ^ Greiner, W. ; Schramm, S. ( 2008 ). `` Resource Letter QEDV - 1 : The QED vacuum ''. American Journal of Physics. 76 : 509. Bibcode : 2008AmJPh... 76... 509G. doi : 10.1119 / 1.2820395., and references therein Jump up ^ Wang, Yang ; Wong, Dillon ; Shytov, Andrey V. ; Brar, Victor W. ; Choi, Sangkook ; Wu, Qiong ; Tsai, Hsin - Zon ; Regan, William ; Zettl, Alex ; Kawakami, Roland K. ; Louie, Steven G. ; Levitov, Leonid S. ; Crommie, Michael F. ( May 10, 2013 ). `` Observing Atomic Collapse Resonances in Artificial Nuclei on Graphene ''. Science. 340 ( 6133 ) : 734 -- 737. arXiv : 1510.02890. Bibcode : 2013Sci... 340... 734W. doi : 10.1126 / science. 1234320. PMID 23470728. Jump up ^ Indelicato, Paul ; Bieroń, Jacek ; Jönsson, Per ( 2011 - 06 - 01 ). `` Are MCDF calculations 101 % correct in the super-heavy elements range ? ''. Theoretical Chemistry Accounts. 129 ( 3 - 5 ) : 495 -- 505. doi : 10.1007 / s00214 - 010 - 0887 - 3. ISSN 1432 - 881X. ^ Jump up to : Emsley, John ( 2011 ). Nature 's Building Blocks : An A -- Z Guide to the Elements ( New ed. ). New York : Oxford University Press. p. 592. ISBN 978 - 0 - 19 - 960563 - 7. Jump up ^ http://www.primefan.ru/stuff/chem/nefedov.pdf Jump up ^ Lougheed, R. ; et al. ( 1985 ). `` Search for superheavy elements using Ca + Es reaction ''. Physical Review C. 32 ( 5 ) : 1760 -- 1763. Bibcode : 1985PhRvC... 32.1760 L. doi : 10.1103 / PhysRevC. 32.1760. Jump up ^ Feng, Z ; Jin, G. ; Li, J. ; Scheid, W. ( 2009 ). `` Production of heavy and superheavy nuclei in massive fusion reactions ''. Nuclear Physics A. 816 : 33. arXiv : 0803.1117. Bibcode : 2009NuPhA. 816... 33F. doi : 10.1016 / j. nuclphysa. 2008.11. 003. Jump up ^ `` Russian physicists plan to synthesize element 119 of periodic system ''. sputniknews.com. 26 March 2011. Jump up ^ `` Element 117 synthesized on Russian atom smasher ''. The Voice of Russia. 7 April 2010. Retrieved 4 October 2015. The Dubna team are now upgrading their smasher ahead of attempts to synthesize Elements 119 and 120 in a series of experiments before 2012. Jump up ^ Modern alchemy : Turning a line, The Economist, May 12, 2012. ^ Jump up to : Superheavy Element Search Campaign at TASCA. J. Khuyagbaatar ^ Jump up to : Zagrebaev, Valeriy ; Karpov, Alexander ; Greiner, Walter ( 2013 ). `` Future of superheavy element research : Which nuclei could be synthesized within the next few years ? '' ( PDF ). Journal of Physics. IOP Publishing Ltd. 420 : 012001. arXiv : 1207.5700. doi : 10.1088 / 1742 - 6596 / 420 / 1 / 012001. Jump up ^ Search for element 119 : Christoph E. Düllmann for the TASCA E119 collaboration ^ Jump up to : Yakushev, A. ( 2012 ). `` Superheavy Element Research at TASCA '' ( PDF ). asrc.jaea.go.jp. Retrieved 23 September 2016. Jump up ^ `` Scientists will begin experiments on the synthesis of element 119 in 2019 ''. www.jinr.ru. JINR. 28 September 2016. Retrieved 31 March 2017. `` The discovery of elements 115, 117 and 118 is an accomplished fact ; they were placed in the periodic table, though still unnamed and will be confirmed only at the end of the year. The D.I. Mendeleev Periodic Table is not infinite. In 2019, scientists will begin the synthesis of elements 119 and 120 which are the first in the 8th period, '' said S.N. Dmitriev. Jump up ^ Dmitriev, Sergey ; Itkis, Mikhail ; Oganessian, Yuri ( 2016 ). Status and perspectives of the Dubna superheavy element factory ( PDF ). Nobel Symposium NS160 -- Chemistry and Physics of Heavy and Superheavy Elements. doi : 10.1051 / epjconf / 201613108001. ^ Jump up to : `` What it takes to make a new element ''. Chemistry World. Retrieved 2016 - 12 - 03. Jump up ^ `` A New Block on the Periodic Table '' ( PDF ). Lawrence Livermore National Laboratory. April 2007. Retrieved 2008 - 01 - 18. Jump up ^ Chowdhury, P. Roy ; Samanta, C. ; Basu, D.N. ( 2008 ). `` Search for long lived heaviest nuclei beyond the valley of stability ''. Physical Review C. 77 ( 4 ) : 044603. arXiv : 0802.3837. Bibcode : 2008PhRvC... 77d4603C. doi : 10.1103 / PhysRevC. 77.044603. Jump up ^ Chowdhury, R.P. ; Samanta, C. ; Basu, D.N. ( 2008 ). `` Nuclear half - lives for α - radioactivity of elements with 100 ≤ Z ≤ 130 ''. Atomic Data and Nuclear Data Tables. 94 ( 6 ) : 781 -- 806. arXiv : 0802.4161. Bibcode : 2008ADNDT... 94... 781C. doi : 10.1016 / j. adt. 2008.01. 003. Jump up ^ Itkis, M.G. ; Oganessian, Yu. Ts. ( 2007 ). `` Synthesis of New Nuclei and Study of Nuclear Properties and Heavy - Ion Reaction Mechanisms ''. jinr.ru. Joint Institute for Nuclear Research. Retrieved 23 September 2016. Jump up ^ Oganessian, Yu. Ts. ; Utyonkov, V. ; Lobanov, Yu. ; Abdullin, F. ; Polyakov, A. ; Sagaidak, R. ; Shirokovsky, I. ; Tsyganov, Yu. ; et al. ( 2009 ). `` Attempt to produce element 120 in the Pu+ Fe reaction ''. Phys. Rev. C. 79 ( 2 ) : 024603. Bibcode : 2009PhRvC... 79b4603O. doi : 10.1103 / PhysRevC. 79.024603. ^ Jump up to : http://fias.uni-frankfurt.de/kollo/Duellmann_FIAS-Kolloquium.pdf Jump up ^ GSI. `` Searching for the island of stability ''. www.gsi.de. GSI. Retrieved 23 September 2016. Jump up ^ Adcock, Colin ( 2 October 2015 ). `` Weighty matters : Sigurd Hofmann on the heaviest of nuclei ''. JPhys+. Journal of Physics G : Nuclear and Particle Physics. Retrieved 23 September 2016. Jump up ^ Hofmann, Sigurd ( August 2015 ). `` Search for Isotopes of Element 120 on the Island of SHN ''. Exotic Nuclei : 213 -- 224. doi : 10.1142 / 9789814699464_0023. ISBN 978 - 981 - 4699 - 45 - 7. Jump up ^ Hofmann, S. ; Heinz, S. ; Mann, R. ; Maurer, J. ; Münzenberg, G. ; Antalic, S. ; Barth, W. ; Burkhard, H.G. ; Dahl, L. ; Eberhardt, K. ; Grzywacz, R. ; Hamilton, J.H. ; Henderson, R.A. ; Kenneally, J.M. ; Kindler, B. ; Kojouharov, I. ; Lang, R. ; Lommel, B. ; Miernik, K. ; Miller, D. ; Moody, K.J. ; Morita, K. ; Nishio, K. ; Popeko, A.G. ; Roberto, J.B. ; Runke, J. ; Rykaczewski, K.P. ; Saro, S. ; Scheidenberger, C. ; Schött, H.J. ; Shaughnessy, D.A. ; Stoyer, M.A. ; Thörle - Popiesch, P. ; Tinschert, K. ; Trautmann, N. ; Uusitalo, J. ; Yeremin, A.V. ( 2016 ). `` Review of even element super-heavy nuclei and search for element 120 ''. The European Physics Journal A. 2016 ( 52 ). Bibcode : 2016EPJA... 52... 180H. doi : 10.1140 / epja / i2016 - 16180 - 4. Jump up ^ Siwek - Wilczyńska, K. ; Cap, T. ; Wilczyński, J. ( April 2010 ). `` How can one synthesize the element Z = 120 ? ''. International Journal of Modern Physics E. 19 ( 4 ) : 500. Bibcode : 2010IJMPE... 19... 500S. doi : 10.1142 / S021830131001490X. Jump up ^ `` Scientists will begin experiments on the synthesis of element 119 in 2019 ''. www.jinr.ru. JINR. 28 September 2016. Retrieved 31 March 2017. ' The discovery of elements 115, 117 and 118 is an accomplished fact ; they were placed in the periodic table, though still unnamed and will be confirmed only at the end of the year. The D.I. Mendeleev Periodic Table is not infinite. In 2019, scientists will begin the synthesis of elements 119 and 120 which are the first in the 8th period, ' said S.N. Dmitriev. Jump up ^ Dmitriev, Sergey ; Itkis, Mikhail ; Oganessian, Yuri ( 2016 ). Status and perspectives of the Dubna superheavy element factory ( PDF ). Nobel Symposium NS160 -- Chemistry and Physics of Heavy and Superheavy Elements. doi : 10.1051 / epjconf / 201613108001. Jump up ^ see Flerov lab annual reports 2000 -- 2004 inclusive http://www1.jinr.ru/Reports/Reports_eng_arh.html ^ Jump up to : Marinov, A. ; Rodushkin, I. ; Kolb, D. ; Pape, A. ; Kashiv, Y. ; Brandt, R. ; Gentry, R.V. ; Miller, H.W. ( 2008 ). `` Evidence for a long - lived superheavy nucleus with atomic mass number A = 292 and atomic number Z = ~ 122 in natural Th ''. International Journal of Modern Physics E. 19 : 131 -- 140. arXiv : 0804.3869. Bibcode : 2010IJMPE... 19... 131M. doi : 10.1142 / S0218301310014662. Jump up ^ Royal Society of Chemistry, `` Heaviest element claim criticised '', Chemical World. ^ Jump up to : Marinov, A. ; Rodushkin, I. ; Kashiv, Y. ; Halicz, L. ; Segal, I. ; Pape, A. ; Gentry, R.V. ; Miller, H.W. ; Kolb, D. ; Brandt, R. ( 2007 ). `` Existence of long - lived isomeric states in naturally - occurring neutron - deficient Th isotopes ''. Phys. Rev. C. 76 ( 2 ) : 021303 ( R ). arXiv : nucl - ex / 0605008. Bibcode : 2007PhRvC... 76b1303M. doi : 10.1103 / PhysRevC. 76.021303. Jump up ^ R.C. Barber ; J.R. De Laeter ( 2009 ). `` Comment on ' Existence of long - lived isomeric states in naturally - occurring neutron - deficient Th isotopes ' ''. Phys. Rev. C. 79 ( 4 ) : 049801. Bibcode : 2009PhRvC... 79d9801B. doi : 10.1103 / PhysRevC. 79.049801. Jump up ^ A. Marinov ; I. Rodushkin ; Y. Kashiv ; L. Halicz ; I. Segal ; A. Pape ; R.V. Gentry ; H.W. Miller ; D. Kolb ; R. Brandt ( 2009 ). `` Reply to `` Comment on ' Existence of long - lived isomeric states in naturally - occurring neutron - deficient Th isotopes ' '' ``. Phys. Rev. C. 79 ( 4 ) : 049802. Bibcode : 2009PhRvC... 79d9802M. doi : 10.1103 / PhysRevC. 79.049802. Jump up ^ J. Lachner ; I. Dillmann ; T. Faestermann ; G. Korschinek ; M. Poutivtsev ; G. Rugel ( 2008 ). `` Search for long - lived isomeric states in neutron - deficient thorium isotopes ''. Phys. Rev. C. 78 ( 6 ) : 064313. arXiv : 0907.0126. Bibcode : 2008PhRvC... 78f4313L. doi : 10.1103 / PhysRevC. 78.064313. Jump up ^ Marinov, A. ; Rodushkin, I. ; Pape, A. ; Kashiv, Y. ; Kolb, D. ; Brandt, R. ; Gentry, R.V. ; Miller, H.W. ; Halicz, L. ; Segal, I. ( 2009 ). `` Existence of Long - Lived Isotopes of a Superheavy Element in Natural Au '' ( PDF ). International Journal of Modern Physics E. World Scientific Publishing Company. 18 ( 3 ) : 621 -- 629. arXiv : nucl - ex / 0702051. Bibcode : 2009IJMPE... 18... 621M. doi : 10.1142 / S021830130901280X. Archived from the original ( PDF ) on July 14, 2014. Retrieved February 12, 2012. Further reading Kaldor, U. ( 2005 ). `` Superheavy Elements -- Chemistry and Spectroscopy ''. Encyclopedia of Computational Chemistry. doi : 10.1002 / 0470845015. cu0044. ISBN 0470845015. Seaborg, G.T. ( 1968 ). `` Elements Beyond 100, Present Status and Future Prospects ''. Annual Review of Nuclear Science. 18 : 53 -- 152. Bibcode : 1968ARNPS... 18... 53S. doi : 10.1146 / annurev. ns. 18.120168. 000413. Scerri, Eric. ( 2011 ). A Very Short Introduction to the Periodic Table, Oxford University Press, Oxford. ISBN 978 - 0 - 19 - 958249 - 5. External links Holler, Jim. `` Images of g - orbitals ''. University of Kentucky. Rihani, Jeries A. `` The extended periodic table of the elements ''. Scerri, Eric. `` Eric Scerri 's website for the elements and the periodic table ''. Extended periodic table ( Large version ) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 He Li Be O Ne Na Mg Al Si Cl Ar Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 5 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te Xe 6 Cs Ba La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Hf Ta Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn 7 Fr Ra Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og 8 119 120 121 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 ‍ ‍ 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 Alkali metal Alkaline earth metal Superactinide Lanthanide Actinide Transition metal Post - ​ transition metal Metalloid Polyatomic nonmetal Diatomic nonmetal Noble gas predicted predicted predicted predicted predicted predicted predicted predicted predicted Periodic table Periodic table forms Standard 18 - column 18 - column, large cells 32 - column, large cells Alternative Alternatives Chemical Galaxy Janet 's left step table Extended Extension beyond the 7th period Fricke model large cells Pyykkö model Sets of elements By periodic table structure Groups 1 ( Alkali metals ) 2 ( Alkaline earth metals ) 5 6 7 8 9 10 11 12 13 14 15 ( Pnictogens ) 16 ( Chalcogens ) 17 ( Halogens ) 18 ( Noble gases ) Periods 5 6 7 8 + Aufbau Fricke Pyykkö Blocks s - block p - block d - block f - block g - block Aufbau principle By metallicity Metals Alkali metals Alkaline earth metals Lanthanides Actinides Superactinides Eka - superactinides Transition metals Post-transition metals Metalloids Lists of metalloids by source Dividing line Nonmetals Polyatomic nonmetals Diatomic nonmetals Noble gases Other sets Nutritional elements Platinum - group metals ( PGM ) Rare - earth elements Refractory metals Precious metals Coinage metals Noble metal Heavy metals Native metals Transuranium elements Transactinide elements Major actinides Minor actinides Elements Lists By : Abundance ( in humans ) Atomic properties Nuclear stability Production Symbol Properties Atomic weight Crystal structure Electron affinity Electron configuration Electronegativity Allen Pauling Goldschmidt classification Maximum valence Data pages Abundance Atomic radius Boiling point Critical point Density Elasticity Electrical resistivity Electron affinity Electron configuration Electronegativity Hardness Heat capacity Heat of fusion Heat of vaporization Ionization energy Melting point Oxidation state Speed of sound Thermal conductivity Thermal expansion coefficient Vapor pressure History Element discoveries Mendeleev 's predictions Naming Etymology controversies places scientists in East Asia See also IUPAC nomenclature systematic element name Trivial name Dmitri Mendeleev Book Category Chemistry Portal Retrieved from `` https://en.wikipedia.org/w/index.php?title=Extended_periodic_table&oldid=808882073 '' Categories : Hypothetical chemical elements Periodic table Hidden categories : All articles with dead external links Articles with dead external links from October 2016 Articles containing potentially dated statements from April 2011 All articles containing potentially dated statements Articles needing expert attention with no reason or talk parameter Articles needing unspecified expert attention Articles needing expert attention from December 2011 All articles needing expert attention All articles with unsourced statements Articles with unsourced statements from February 2012 All articles with specifically marked weasel - worded phrases Articles with specifically marked weasel - worded phrases from October 2011 Talk Contents About Wikipedia Asturianu বাংলা Čeština Deutsch Ελληνικά Español Esperanto Français 한국어 Bahasa Indonesia Italiano മലയാളം 日本 語 Polski Português Română Русский Simple English Slovenčina Slovenščina Српски / srpski Suomi Svenska ไทย Türkçe 粵語 中文 Edit links This page was last edited on 5 November 2017, at 20 : 09. Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia ® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. About Wikipedia

Question: what is the atomic number of the yet undiscovered element directly below ra in the periodic table
Answer: 120