|Name in Saurian|| Vhuidxevohaim (Vx)|
|Systematic name|| Unhexunium (Uhn)|
|Location on the periodic table|
|Above element||Meitnerium (109Mt)|
|Previous element||Hundium (160Hu)|
|Next element||Madelungium (162Ma)|
|Atomic mass||465.8680 u, 773.5919 yg|
|Atomic radius||199 pm, 1.99 Å|
|Van der Waals radius||238 pm, 2.38 Å|
|Nucleons||462 (161 p+, 301 n0)|
|Nuclear radius||9.24 fm|
|Electron configuration|| [Mc] 5g18 6f14 7d6 8s2 8p2 9s1|
2, 8, 18, 32, 50, 32, 14, 4, 1
|Oxidation states|| −1, 0, +1, +2, +3, +4,|
+5, +6, +7, +8, +9
(strongly basic oxide)
|First ionization energy||475.8 kJ/mol, 4.931 eV|
|Electron affinity||34.9 kJ/mol, 0.362 eV|
|Covalent radius||201 pm, 2.01 Å|
|Molar mass||465.868 g/mol|
|Molar volume||11.617 cm3/mol|
|Atomic number density||5.18 × 1022 cm−3|
|Average atomic separation||268 pm, 2.68 Å|
|Speed of sound||4743 m/s|
|Crystal structure||Body centered cubic|
|Melting point|| 682.60 K, 409.45°C|
|Boiling point|| 2604.95 K, 2331.80°C|
|Liquid range||1922.35 K/°C, 3460.24°F/°R|
|Triple point|| 682.61 K, 409.46°C|
@ 133.58 nPa, 1.0019 × 109 torr
|Critical point|| 7752.17 K, 7479.02°C|
@ 78.0914 MPa, 770.704 atm
|Heat of fusion||6.014 kJ/mol|
|Heat of vaporization||221.291 kJ/mol|
|Heat capacity|| 0.05715 J/g/K, 0.10287 J/g/°R|
26.626 J/mol/K, 47.926 J/mol/°R
|Universe (by mass)|| Relative: 6.74 × 10−38|
Absolute: 2.26 × 1015 kg
Fraunhoferium is the fabricated name of a hypothetical element with the symbol Fh and atomic number 161. Fraunhoferium was named in honor of Joseph von Fraunhofer (1787–1826), who revolutionized spectroscopy by discovering dark absorption lines on the spectrum, which are fingerprints for identifying elements or compounds. This element is known in scientific literature as unhexunium (Uhu), dvi-iridium, or simply element 161. Fraunhoferium is the heaviest member of the cobalt family (below cobalt, rhodium, iridium, and meitnerium) and is the seventh member of the vanthoffide series; this element is located in periodic table coordinate 7d7.
Unlike most metals, fraunhoferium is not silvery, but a dark green metal, caused by the interactions of electrons in the s- and d-orbitals oscillating weakly at wavelengths in the green region of the spectrum. Fraunhoferium is solid up to 769°F (683 K), and be gaseous above 4229°F (2605 K). It is very dense, densing at 40 g/cm3, more than four times denser than iron. The atoms arrange to form body centered cubic crystal lattices with an average separation of 268 pm.
Fraunhoferium's atom masses 465.868 daltons; the mass of the nucleus is just barely less than the mass of the atom at 465.780 daltons. The nucleus is comprised of 161 protons and 301 neutrons, corresponding to its nuclear ratio of 1.87, meaning the atom has 1.87 neutrons per proton.
There are 161 electrons in 25 orbitals (9 shells). The electron configuration is [Ms] 5g18 6f14 7d6 8s2 8p2 9s1, strongly disagreeing with the element's placement on the periodic table. Notice that there is one electron in the ninth shell even though it is not a period 9 element because of the extreme relativistic effects causing high spin-orbit coupling, leaving 7d orbital with just six instead of seven electrons.
Like every other trans-lead elements, fraunhoferium has no stable isotopes. The most stable isotope is 462Fh with a half-life (t½) of 28.6 seconds. It undergoes spontaneous fission, splitting into two or three lighter nuclei as well as neutrons like the following examples.
464Fh has a half-life of 2.36 seconds. Like most elements, fraunhoferium has several meta states with half-lives of at least a nanosecond. The most stable metastable fraunhoferium isotope is 461m3Fh, whose half-life is as long as three days, 461m2Fh two hours, and 461m1Fh three kiloseconds. Like the parent ground state isotope whose fission half-life is just 1.46 seconds, they all undergo spontaneous fission.
Since fraunhoferium lies below other cobalt family members, its chemistry should resemble other members like cobalt and iridium. But however due to an electron in the 9s orbital due to spin-orbit coupling, fraunhoferium would instead behave much more like an alkali metal than a transition metal, thus making fraunhoferium very reactive unlike other members of the group. For lighter cogeners, electronegativities and ionization energies increase as going further down in the group, but there is a sudden drop-off at fraunhoferium. Its electronegativity is 0.88 and first ionization energy is 4.93 eV, for comparison cobalt has the electronegativity of 1.88 and first ionization energy 7.64 eV, both second to fraunhoferium. Due to the presence of an electron in the loosely bound 9s orbital, fraunhoferium can form many stable monovalent compounds with a +1 oxidation state. Like alkali metals, it can form ionic bonds with nonmetals, such as fluorine (FhF), chlorine (FhCl), and oxygen (Fh2O). These compounds would have high melting and boiling points due to the strength of ionic bonds. Also like alkali metals, fraunhoferium forms sky blue +1 ions (Fh+) in aqueous solutions.
In addition to +1 state, +3 state is also stable by donating all two electrons in the 8p1/2 suborbital in addition to one in the 9s orbital. In the +3 state, fraunhoferium can behave more like a transition metal and forms colorless solution of Fh3+ ions. There are other less stable oxidation states, including −1, +2, and beyond +3 up to +9.
Fraunhoferium most easily forms binary halides, such as FhF and FhCl, both white ionic salts similar in appearance to NaCl. Other monohalides are FhBr and FhI, both yellow ionic salts. Fraunhoferium loses greenish color when exposed to air to form a brownish black Fh2O. Fh2O3 can be created when the metal or suboxide is heated slightly with pure oxygen. It is a vivid red powder that decomposes at 1454°F (1063 K). The sulfur homologues of oxides are Fh2S and Fh2S3, which are white and bright amber-colored powder respectively. Fh4C3, Fh4C, and FhC are refractory gray semiconducting solids, as well as corresponding silicides.
Fraunhoferium can form neutral salts like Fh2SiO3 and Fh2CO3 when the metal dissolves in silicic acid and carbonic acid, respectively. Fraunhoferium hydroxide, FhOH, is obtained when the metal reacts vigorously with water. Unlike typical transition metal hydroxides, which are weak bases, FhOH is a very strong base like NaOH.
It can also form organic compounds called organofraunhoferium compounds like fraunhoferium sugars and fraunhoferium alcohols. Like inorganic compounds, +1 oxistate is predominant in organic compounds. For example, fraunhoferium replaces hydrogen atom in sucrose to make C12O22H10Fh (fraunhoferium sucrose), while it replaces hydrogen atom in ethane or hydroxide in ethanol to make C2H5Fh (monoethylfraunhoferium). These compounds are similar in appearance to corresponding ordinary compounds.
Occurrence and synthesis Edit
It is almost certain that fraunhoferium doesn't exist on Earth at all, but it is believed to exist somewhere in the universe, at least in very tiny amounts. Since every element heavier than lithium were produced by stars, then fraunhoferium must be produced in stars, and then thrown out into space by exploding stars. But it is theoretically 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 heavy element. Instead, this element virtually can only be made by advanced technological civilizations. An estimated abundance of fraunhoferium in the universe by mass is 6.74 × 10−38, which amounts to 2.26 × 1015 kilograms.
To go along with other such civilizations, humans on Earth may eventually have the capability to synthesize fraunhoferium. To synthesize most stable isotopes of fraunhoferium, nuclei of a couple lighter elements must be fused together, and right amount of neutrons must be seeded. This operation would be extremely difficult since it requires vast amounts of energy and even if nuclei of this element were produced would immediately decay due to its brief half-life. Here's couple of example equations in the production of the most stable isotope 462Fh.