|Named after||Jacobus Henricus van 't Hoff|
|Name in Saurian|| Ludkxevvaim (Lx)|
|Systematic name|| Unpentpentium (Upp)|
|Location on the periodic table|
|Element above Vanthoffium||Mendelevium|
|Element left of Vanthoffium||Lewisium|
|Element right of Vanthoffium||Hawkinium|
|443.6824 u, 736.7519 yg|
|Atomic radius||124 pm, 1.24 Å|
|Covalent radius||132 pm, 1.32 Å|
|van der Waals radius||183 pm, 1.83 Å|
|s||440 (155 p+, 285 no)|
|Electron configuration||[Og] 5g18 6f12 7d3 8s2 8p2|
|Electrons per shell||2, 8, 18, 32, 50, 30, 11, 4|
|Oxidation states|| 0, +1, +2, +3, +4, +5|
(a mildly basic oxide)
|First ionization energy||954.0 kJ/mol, 9.887 eV|
|Electron affinity||29.2 kJ/mol, 0.303 eV|
|Molar mass||443.682 g/mol|
|Molar volume||26.119 cm3/mol|
|Atomic number density|| 1.36 × 1021 g−1|
2.31 × 1022 cm−3
|Average atomic separation||351 pm, 3.51 Å|
|Melting point|| 1548.37 K, 2787.07°R|
|Boiling point|| 3694.19 K, 6649.54°R|
|Liquid range||2145.82 , 3862.47|
|Triple point|| 1548.36 K, 2787.05°R|
@ 7.3523 mPa, 5.5147 × 10−5 torr
|Critical point|| 8988.59 K, 16179.46°R|
@ 1.4675 MPa, 14.483 atm
|Heat of fusion||17.039 kJ/mol|
|Heat of vaporization||115.293 kJ/mol|
|Heat capacity|| 0.05056 J/(g• ), 0.09100 J/(g• )|
22.431 J/(mol• ), 40.376 J/(mol• )
|Abundance in the universe|
|By mass|| Relative: 5.00 × 10−33|
Absolute: 1.68 × 1020 kg
|By atom||2.96 × 10−34|
Vanthoffium is the provisional non-systematic name of a theoretical element with the symbol Vh and atomic number 155. Vanthoffium was named in honor of Jacobus Henricus van 't Hoff (1852–1911), who made discoveries in chemical kinetics, chemical equilibrium, osmotic pressure, and stereochemistry. This element is known in the scientific literature as unpentpentium (Upp), eka-mendelevium, or simply element 155. Vanthoffium is the thirteenth member of the dumaside series, found in the third row of f-block (below thulium and mendelevium); this element is located in the periodic table coordinate 6f13.
Atomic properties Edit
Vanthoffium's nucleus comprises of 440 particles (155 protons, 285 neutrons), which together make up almost all of atom's mass packed into such a tiny portion of the atom in volume. The electron configuration and electrons per shell is not what the periodic table would tell because of the spin-orbit coupling due to relativistic effects. As it is the second-to-last element of the f-block series, it should need just one more electron for its orbital to be full, but an electron is missing due to spin-orbit coupling. The missing f-orbital electron belongs in the d-orbital.
Like every other element heavier than lead, vanthoffium has no stable isotopes. The longest-lived isotope is 440Vh with a half-life of only 4.6 milliseconds. It undergoes spontaneous fission, splitting into two or three lighter nuclei plus neutrons like the examples.
Every vanthoffium meta states have half-lives shorter than the longest-lived ground state isotope 440Vh, which is unusual for elements heavier than arrhenium. 443m2Vh has half-life is 2.7 milliseconds. The second longest half-life is 370 microseconds, for 442mVh.
Chemical properties and compounds Edit
Vanthoffium is very unreactive due to its unexpectedly small atomic size caused by high charge density between so many protons and electrons. The most stable oxidation state is +1 (monovalent), and can donate no more than three electrons. Hence this, Vh+ ions is most stable in aqueous solutions, coloring light orange in water but dark red in acetylene. Vanthoffium has the highest ionization energy of any scandium family elements at 9.9 eV. The second highest ionization energy is scandium, 6.6 eV. In response, vanthoffium has the highest electronegativity with the second highest is again scandium.
There are examples of vanthoffium compounds despite its noble feature of the element. Vanthoffium(III) nitride (VhN) is a peach crystalline solid. Vanthoffium(V) oxide (Vh2O5) is a red powder. Vanthoffium trinitrate (Vh(NO3)3) is colored green as a powder or in solution. Vanthoffium(V) chloride (VhCl5) is a blue ionic solid obtained by reacting either with hydrochloric acid or chlorine gas. Vanthoffium(I) cyanide (VhCN) is a volatile white powder and vanthoffium sulfate (VhSO4) is a pale yellow powder. Vanthoffium can also form compounds in the +0 state, such as Vh(SN)2 and Vh(CO)5.
It is almost certain that vanthoffium 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, this element can only be produced by advanced technological civilizations, virtually accounting for all of its abundance in the universe. Vanthoffium has an estimated abundance of 5 × 10−33 by mass, which amounts to 1.68 × 1020 kilograms.
To synthesize most stable isotopes of vanthoffium, 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. Even if synthesis succeeds, this resulting element would immediately undergo fission. Here's couple of example equations in the synthesis of the most stable isotope, 440Vh.