|Named after||Friedrich Hund|
|Name in Saurian|| Xidtaim (Xi)|
|Systematic name|| Unhexnilium (Uhn)|
|Location on the periodic table|
|Element above Hundium||Seaborgium|
|Element left of Hundium||Vanderwaalsium|
|Element right of Hundium||Fraunhoferium|
|460.8255 u, 765.2187 yg|
|Atomic radius||204 pm, 2.04 Å|
|Covalent radius||209 pm, 2.09 Å|
|van der Waals radius||246 pm, 2.46 Å|
|s||457 (160 p+, 297 no)|
|Electron configuration||[Og] 5g18 6f14 7d5 8s2 8p2 9s1|
|Electrons per shell||2, 8, 18, 32, 50, 32, 13, 4, 1|
|Oxidation states|| −1, 0, +1, +2, +3, +4,|
+5, +6, +7, +8, +10
(a strongly basic oxide)
|First ionization energy||428.5 kJ/mol, 4.441 eV|
|Electron affinity||88.4 kJ/mol, 0.916 eV|
|Molar mass||460.825 g/mol|
|Molar volume||12.695 cm3/mol|
|Atomic number density|| 1.31 × 1021 g−1|
4.74 × 1022 cm−3
|Average atomic separation||276 pm, 2.76 Å|
|Melting point|| 571.10 K, 1027.98°R|
|Boiling point|| 2233.50 K, 4020.30°R|
|Liquid range||1662.40 , 2992.33|
|Triple point|| 571.10 K, 1027.99°R|
@ 1.6875 nPa, 1.2657 × 10−11 torr
|Critical point|| 6155.40 K, 11079.72°R|
@ 86.3590 MPa, 852.300 atm
|Heat of fusion||5.117 kJ/mol|
|Heat of vaporization||189.512 kJ/mol|
|Heat capacity|| 0.05560 J/(g• ), 0.10008 J/(g• )|
25.623 J/(mol• ), 46.122 J/(mol• )
|Abundance in the universe|
|By mass|| Relative: 2.18 × 10−30|
Absolute: 7.31 × 1022 kg
|By atom||1.24 × 10−31|
Hundium is the provisional non-systematic name of a theoretical element with the symbol Hu and atomic number 160. Hundium was named in honor of Friedrich Hund (1896–1997), who governed the electron configurations with maximum multiplicity (known as Hund's rules). This element is known in the scientific literature as unhexnilium (Uhn), dvi-tungsten, or simply element 160. Hundium is the heaviest member of the chromium family (below chromium, molybdenum, tungsten, and seaborgium) and is the fourth member of the kelvinide series; this element is located in the periodic table coordinate 7d4.
Atomic properties Edit
Because of the extreme relativistic effects, an electron is occupying in the 9s orbital, even though it is a period 8 element. It has 160 electrons in 9 shell and 25 orbitals. Because it has so many shells and orbitals, the atom must be large, but because of the electric forces between so many electrons and so many protons, the atom only measures 134 picometers, almost identical in size to iodine atom, whose radius is 133 pm.
Hundium's atom masses 461 daltons, calculated by adding masses of all of the atomic components altogether. 99.98% of all mass are concentrated in the nucleus, which is tiny compared to the size of the atom. Also the nucleus contains most of atomic particles (at 74%), albeit much more moderate than mass and size of nucleus relative to atom. There are two types of particles that make up the nucleus, protons and neutrons. The nucleus has a ratio of 1.86, meaning it contains 86% more neutrons (297) than protons (160).
Like every other element heavier than lead, hundium has no stable isotopes. The longest-lived isotope is 457Hu with a fission half-life of 35 minutes, which is unusually long for elements in this region of the periodic table in terms of atomic numbers.
This element is near the center of the "second island of stability." Another isotope, 453Hu, has a half-life of 1.35 minutes. All of the remaining isotopes have half-lives less than 20 seconds and the majority of these have half-lives less than 1 second. Hundium has isomers like more than 90% of elements on the 172-element periodic table. The most stable isomer has a half-life of 2.5 seconds for 454mHu, about 1⁄840 the half-life of 457Hu. 456mHu has a half-life of 403 milliseconds and 459mHu has a half-life of 13 milliseconds. Every other isomers have half-lives less than a millisecond.
Chemical properties and compounds Edit
Hundium's most stable oxistate is +2 due to its readiness to give up the only electron in the ninth shell plus one in the 7d5/2 subshell, thus hundium would most commonly form divalent compounds. The other oxidation states range from −1 to +10. Its electronegativity is 0.82 and first ionization energy 4.4 eV, thus making hundium a very reactive element unlike all the lighter cogeners. It would quickly tarnish when exposed to air and would burn brilliant orange when in powdered form. It would react very readily with mineral acids to form salts and with water to form a strong base. When dissolved, it most easily dissociates into hundium (Hu+) ions forming light pink solution.
Examples of oxides are Hu2O, HuO, HuO3 and HuO4. The carbides are Hu4C, Hu2C, Hu2C3 and HuC2. HuCO3 is a white powder form which can be made when hundium(II) oxide reacts with carbon dioxide. Hundium can form halides, the most stable is dihalides, which are HuF2, HuCl2, HuBr2, and HuI2. These compounds are ionic comprising of Hu2+ and X−.
- Hu2SO4 + 2 C → Hu2S + 2 CO2
Hundium sodium zinc carbon oxide (HuNa2Zn3CO11) is a superconductor if its below 268 K (−5°C, 23°F, 483°R), very near the freezing point of water.
Like almost every other element, hundium can form organic compounds, called organohundium. Examples are Hu(CO)8 (hundium octacarbonyl), Me4Hu (methylhundium), HuC6H5O7 (hundium citrate), and C4H8Cl2Hu (bis(2-chloroethyl)hundium).
Physical properties Edit
At ordinary conditions, hundium is a purplish gray metal that is ductile, malleable, and lustrous. With the density of 36.3 g/cm3, the element is 1.9 times denser than the other family member tungsten (9.64 g/cm3). Hundium atoms forming cubic crystals are close together, at an average distance of just 276 picometers between atoms. Consequently, there are a lot of atoms in one cubic centimeter (47.4 sextillion) of metal compared to other elements.
Like most other metals, hundium is solid at room temperature (298 K, 537°R), most with melting points above 1000 K (1800°R). However the melting point of this metal is only 571 K (1028°R), which is very unlike other elements of the chromium family due to its unique electron configuration featuring an electron in the 9s orbital beyond five-electron 7d orbital and two-electron 8p orbital. The boiling point is almost four times higher than its melting point, at 2234 K (4020°R).
It is almost certain that hundium doesn't exist on Earth at all, but it is believe to barely exist somewhere in the universe due to its brief lifetime. Every element heavier than iron can only naturally be produced by exploding stars. But it is likely 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, hundium can only be produced by advanced technological civilizations, virtually accounting for all of its abundance in the universe. An estimated abundance of hundium in the universe by mass is 2.18 × 10−30, which amounts to 7.31 × 1022 kilograms, which is almost exactly the same amount it takes to make the object the mass of our moon made out of pure hundium.
To synthesize most stable isotopes of hundium, 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, 457Hu.