|Name in Saurian|| Ulewuthaim (Ul)|
|Systematic name|| Unquadennium (Uqe)|
|Location on the periodic table|
|Above element||Berkelium (97Bk)|
|Previous element||Faradium (148Fa)|
|Next element||Schrodium (150So)|
|416.4535 u, 691.5372 yg|
|Atomic radius||127 pm, 1.27 Å|
|Van der Waals radius||173 pm, 1.73 Å|
|s||413 (149 p+, 264 n0)|
|Electron configuration|| [Mc] 5g18 6f6 7d3 8s2 8p2|
2, 8, 18, 32, 50, 24, 11, 4
|Oxidation states|| 0, +1, +2, +3|
(weakly basic oxide)
|First ionization energy||868.0 kJ/mol, 8.996 eV|
|Electron affinity||71.6 kJ/mol, 0.742 eV|
|Covalent radius||142 pm, 1.42 Å|
|Molar mass||416.453 g/mol|
|Molar volume||28.090 cm3/mol|
|Atomic number density|| 1.45 × 1021 g−1|
2.14 × 1022 cm−3
|Average atomic separation||360 pm, 3.60 Å|
|Crystal structure||Face centered cubic|
|Melting point|| 688.25 K, 1238.85°R|
|Boiling point|| 4700.20 K, 8460.36°R|
|Liquid range||4011.95 , 7321.51|
|Triple point|| 688.15 K, 1238.67°R|
@ 8.4910 × 10−14 aPa, 6.3688 × 10−34 torr
|Critical point|| 14006.59 K, 25211.86°R|
@ 178.9003 MPa, 1765.614 atm
|Heat of fusion||6.160 kJ/mol|
|Heat of vaporization||432.598 kJ/mol|
|Heat capacity|| 0.05738 J/(g• ), 0.10328 J/(g• )|
23.895 J/(mol• ), 43.011 J/(mol• )
|Universe (by mass)|| Relative: 9.54 × 10−38|
Absolute: 3.20 × 1015 kg
Avogadrium is the fabricated name of a hypothetical element with the symbol Av and atomic number 149. Avogadrium was named in honor of Amedeo Avogadro (1776–1856), who developed the molecular theory, determined the number of particles in one mole of substance (known as Avogadro constant), and contributed gas law. This element is known in the scientific literature as unquadennium (Uqe), eka-berkelium, or simply element 149. Avogadrium is the ninth member of the dumaside series, found in the third row of f-block (below terbium and berkelium); this element is located in the periodic table coordinate 6f9.
Avogadrium is a bright, vivid yellow metal that is malleable and ductile. Avogadrium(III) ions fluorescences in brilliant red light at 636 nm. The molar mass is 4164⁄9 g/mol while its molar volume is 281⁄11 cm3/mol; dividing molar mass and volume yields a density of 145⁄6 g/cm3. Its speed of sound is 5059 m/s and its lattice is in the form of face centered cubic.
Avogadrium has the widest liquid range of any element. Liquid avogadrium ranges from 1239°R (779°F) (melting point) to roughly 8460°R (8001°F) (boiling point). It has the second widest liquid range (7322 ) and the third highest liquid ratio (6.83) of any element. A reason why the liquid range and quotient is so wide is because of an exceptionally low vapor pressure despite its low melting point, due to strong metallic bonding of liquid metal. Due to this, the amount of energy needed to convert from liquid to gas during boiling (called heat of vaporization) is merely 70 times greater than energy needed to convert from solid to liquid during melting (called heat of fusion), which is 3½ times the average ratio of 20. Its triple point, a point on the phase diagram where solid, liquid, and gas coexist in equilibrium, is at a temperature 0.18 lower than its melting point but at near-zero pressure of 8.49 × 10−32 Pa.
Avogadrium atom masses 416.45 daltons and sizes 152 pm in radius. It has 562 component particles, 73% of all components lie in a region only approximately 1⁄14000 the radius of the atom, which is the atomic nucleus with the same value of charge as its atomic number. Outside the nucleus, the electron notation is 149-8-24, meaning there are 149 electrons in 8 shells and 24 orbitals.
Like every other element heavier than lead, avogadrium has no stable isotopes. The most stable isotope is 413Av with a fission half-life of 414⁄5 milliseconds. Fission means splitting into two or three lighter nuclei plus neutrons like the example.
Like every element heavier than calcium, avogadrium has metastable isomers. The longest lived isomer is 413m1Av with a half-life of 5.6 milliseconds. The most stable isomer is shorter lived than the most stable ground state isotope, unlike a lot of elements heavier than arrhenium.
Because of the smearing out the orbitals with filled g-orbital and partially filled f-orbital, avogadrium is an unreactive element, meaning it does not display eka-berkelium properties despite the relative locations on the periodic table. As a result, avogadrium is corrosion-resistent, either in air, water, or acids, though slightly soluble in acids. The element displays a +3 oxidation state like berkelium, as well as +1 and rarely +2. Av3+ is the only stable ion in aqueous solutions. This ion forms purple solution in hydrochloric acid, but crimson in carbonic acid.
Despite its unreactivity, avogadrium has several notable compounds as well as organoavogadrium compounds. Avogadrium monofluoride (AvF) and trifluoride (AvF3) are both white ionic salts appearing like sodium chloride (NaCl). AvCl is a sky blue ionic or crystalline salt while AvCl3 is white. If we put avogadrium in the flame for a few minutes, it first melts to a thick yellow liquid quickly and then tarnishes and solidifies to a brittle brown oxide Av2O, which with further exposure to the flame darkens this substance even more as it oxidizes to Av2O3, which is brownish black and crumbly.
Other than oxides and halides, there are other avogadrium compounds of note. Av2S is a red powder that is soluble in water. Av(SiO2)2 is a gray crystalline solid. Av(PF3)4 is a white crystalline solid that dephosphorizes in salt water to give AvF3, phosphoric acid (H3PO4), PF3, and few other products.
- Av(PF3)4 + 6 H2O + 2 NaCl → AvF3 + H3PO4 + 3 PF3 + 2 NaOH + 2 HCl + 2.5 H2
Organoavogadrium compounds include AvHCO2 (avogadrium formate), AvCH3CO2 (avogadrium acetate), and AvCH3 (methylavogadrium or avogadrium methanide).
Occurrence and synthesis Edit
It is almost certain that avogadrium doesn't exist on Earth at all, but it is believe to exist somewhere in the universe, at least barely. Since every element heavier than lithium were produced by stars, then avogadrium 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 hyperheavy element. Instead, this element virtually can only be made by advanced technological civilizations. An estimated abundance of avogadrium in the universe by mass is 9.54 × 10−38, which amounts to 3.20 × 1015 kilograms.
To go along with other such civilizations, humans on Earth may eventually have the capability to synthesize avogadrium. To synthesize most stable isotopes of avogadrium, 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 a vast amount 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, 413Av.