|Named after||Richard Feynman|
|Name in Saurian|| Voødmudaim (Vø)|
|Systematic name|| Untriseptium (Uts)|
|Location on the periodic table|
|Element left of Feynmanium||Cavendishium|
|Element right of Feynmanium||Chadwickium|
|377.1256 u, 626.2318 yg|
|Atomic radius||149 pm, 1.49 Å|
|Covalent radius||172 pm, 1.72 Å|
|van der Waals radius||170 pm, 1.70 Å|
|s||374 (137 p+, 237 no)|
|Electron configuration||[Og] 5g11 6f4 8s2 8p2|
|Electrons per shell||2, 8, 18, 32, 43, 22, 8, 4|
|Oxidation states|| +4, +5, +6|
(a mildly basic oxide)
|First ionization energy||624.9 kJ/mol, 6.476 eV|
|Electron affinity||54.2 kJ/mol, 0.562 eV|
|Molar mass||377.126 g/mol|
|Molar volume||57.478 cm3/mol|
|Atomic number density|| 1.60 × 1021 g−1|
1.05 × 1022 cm−3
|Average atomic separation||457 pm, 4.57 Å|
|Melting point|| 589.26 K, 1060.67°R|
|Boiling point|| 1608.36 K, 2895.05°R|
|Liquid range||1019.10 , 1834.38|
|Triple point|| 589.11 K, 1060.40°R|
@ 32.479 μPa, 2.4361 × 10−7 torr
|Critical point|| 3286.59 K, 5915.86°R|
@ 44.0152 MPa, 434.398 atm
|Heat of fusion||6.305 kJ/mol|
|Heat of vaporization||158.766 kJ/mol|
|Heat capacity|| 0.05560 J/(g• ), 0.10008 J/(g• )|
20.969 J/(mol• ), 37.744 J/(mol• )
|Abundance in the universe|
|By mass|| Relative: 6.03 × 10−31|
Absolute: 2.02 × 1022 kg
|By atom||4.20 × 10−32|
Feynmanium is the provisional non-systematic name of an undiscovered element with the symbol Fy and atomic number 137. Feynmanium was named in honor of Richard Feynman (1918–1988), who worked in the path integral formulation of quantum mechanics, quantum electrodynamics, and particle physics. This element is known in the scientific literature as untriseptium (Uts) or simply element 137. Feynmanium is the seventeenth element of the lavoiside series and located in the periodic table coordinate 5g17.
Relativistic problems Edit
Feynman, whom this element was named, noted that a simplistic interpretation of the relativistic Dirac equation runs into problems with electron orbitals at Z > 1/α = 137, suggesting that neutral atoms cannot exist beyond feynmanium, and that a periodic table of elements based on electron orbitals therefore breaks down at this point. However, a more rigorous analysis calculates the limit to be Z ≈ 173.
The main reason that 137 isn't the highest possible atomic number is right there in that one word - "simplistic". Feynmann's conjecture was based off what was essentially a slightly modified version of Bohr's atomic model, which we now know to be inaccurate. Furthermore, the prediction did not take into account quantum effects, which are extremely important on the atomic level.
When quantum electrodynamics and a full interpretation of relativity are considered, there appears to be no set upper limit to the mass of an atomic nucleus, although things do start to get weird around N=173 or so.
Note that even these calculations don't take into consideration the strong and weak nuclear forces (mostly because a full mathematical description of both of these forces is still an incredibly difficult problem to create). Given that these forces are perhaps the most important when considering atomic physics, it's likely that such a solution (if we ever find one) would force us to completely reconsider both of these calculations.
TL;DR: 137 is based on a simplified atomic model. Quantum electrodynamics predicts strange effects at N=173+, but no hard cap. Inability to fully understand strong and weak nuclear forces will probably cause us to have to recompute all of this in the future.
Atomic properties Edit
Feynmanium's electron configuration is assumed to be [Og] 5g17 8s2, but due to smearing of the orbitals due to the small separation between the orbitals, the electron configuration is [Og] 5g11 6f4 8s2 8p2. Electrons orbit the nucleus in eight energy levels. Nucleus conprises of 137 protons and 237 neutrons, corresponding to its nuclear ratio of 1.73. The atom masses 377.1 u and sizes at 1.73 angstroms.
Like every other element heavier than lead, feynmanium has no stable isotopes. The longest-lived isotope is 374Fy with a half-life of only 23 seconds. It undergoes spontaneous fission, splitting into two lighter nuclei plus neutrons like the example.
There are four other isotopes having half-lives of at least one second, all undergoing fission. Feynmanium has several meta states, the most stable is 378m1Fy (half-life: 2.8 minutes (167 seconds)).
Chemical properties and compounds Edit
Feynmanium's oxidation state are +4, +5, and +6 with +4 being most common. Its electronegativity on the Pauling scale is 1.44, meaning it is reactive, but not very. It can form hybrids, meaning it changes orbitals when bonded to other element.
In the elemental form, feynmanium slowly tarnishes in the air, reacts slowly in cold water but vigorously in hot water to form a hydroxide. Feynmanium forms basic oxide, meaning it neutralizes acids to form salt by liberating hydrogen gas. Fy4+ forms greenish yellow aqueous solutions.
Feynmanium slowly darkens in the air to form feynmanium(IV) oxide (FyO2), which is black and brittle. Another chalcide is FyS2, which is black crystalline solid. It can form halides of course, such as FyF6, FyCl5, FyBr4, and FyI4, fluoride and chloride are white ionic crystals while bromide and iodide are pale purple powdery crystals.
Feynmanium can form aqueous solutions, such as colorless feynmanium nitrate (Fy(NO3)4), and is a white salt when not in solution.
This metal can form organofeynmanium, such as Fy(C5H5)5 (cyclopentadienylfeynmanium) and (C5H11)5Fy (pentylfeynmanium).
Physical properties Edit
Feynmanium is a gray metal with a density of 6.6 g/cm3 and its speed of sound is 3388 m/s. In one cubic centimeter of metal, there are 1 × 1022 (10 sextillion) atoms, roughly the number of stars in the observable universe. If feynmamium has the average volume of an adult human, atoms number at 1.1 × 1027 (1.1 octillion). It forms hexagonal crystals that transforms to face-centered cubic when cooled to −183°F.
Feynmanium has a melting point of 601°F and boiling point 2435°F. Below its melting point, feynmanium exists as a solid state, at between melting and boiling points, it exists as a liquid state, and above its boiling point, it exists as a gaseous state. The triple point, condition where all three states of feynmanium coexist in equilibrium, is 600.73°F and 32.5 μPa; the critical point, minimum temperature and pressure where supercritical fluid of feynmanium is stable, is 5456°F and 44 MPa.
It is almost certain that feynmanium doesn't exist on Earth at all, but it is believe to barely exist somewhere in the universe due to its very short lifetime. Every element heavier than iron can only naturally be produced by exploding stars. But it is virtually impossible for even the most powerful supernovae or most violent neutron star collisions to produce this element through r-process because there's not enough energy available or not enough neutrons, respectively, to produce this hyperheavy element. . Instead, this element can only be produced by advanced technological civilizations, virtually accounting for all of its abundance in the universe. An estimated abundance of feynmanium in the universe by mass is 6.03 × 10−33, which amounts to 2.02 × 1020 kilograms.
To synthesize most stable isotopes of feynmanium, nuclei of a couple lighter elements must be fused together, and right amount of neutrons must be seeded. This operation would be impossible using current technology since it requires a tremendous amount of energy, thus its cross section would be so low that it is beyond the technological limit. Here's couple of example equations in the synthesis of the most stable isotope, 374Fy.