|Name in Saurian|| Tuløim (Tu)|
|Systematic name|| Unquadhexium (Uqh)|
|Location on the periodic table|
|Above element||Plutonium (94Pu)|
|Previous element||Heisenbergium (145Hi)|
|Next element||Boltzmannium (147Bo)|
|Atomic mass||405.3607 u, 673.1172 yg|
|Atomic radius||136 pm, 1.36 Å|
|Van der Waals radius||182 pm, 1.82 Å|
|Nucleons||402 (146 p+, 256 n0)|
|Nuclear radius||8.82 fm|
|Electron configuration|| [Mc] 5g18 6f4 7d2 8s2 8p2|
2, 8, 18, 32, 50, 22, 10, 4
|Oxidation states|| 0, +2, +3|
(mildly basic oxide)
|First ionization energy||816.2 kJ/mol, 8.459 eV|
|Electron affinity||83.5 kJ/mol, 0.866 eV|
|Covalent radius||149 pm, 1.49 Å|
|Molar mass||405.361 g/mol|
|Molar volume||32.683 cm3/mol|
|Atomic number density|| 1.49 × 1021 g−1|
1.84 × 1022 cm−3
|Average atomic separation||379 pm, 3.79 Å|
|Speed of sound||3670 m/s|
|Crystal structure||Base centered orthorhombic|
|Melting point|| 1386.39 K, 2495.51°R|
|Boiling point|| 3437.26 K, 6187.07°R|
|Liquid range||2050.86 K, 3691.56°R|
|Triple point|| 1385.70 K, 2494.25°R|
@ 4.7163 Pa, 0.035375 torr
|Critical point|| 8506.97 K, 15312.54°R|
@ 520.9138 MPa, 5141.035 atm
|Heat of fusion||14.583 kJ/mol|
|Heat of vaporization||356.464 kJ/mol|
|Heat capacity|| 0.05585 J/(g•K), 0.10053 J/(g•°R)|
22.638 J/(mol•K), 40.749 J/(mol•°R)
|Universe (by mass)|| Relative: 2.82 × 10−32|
Absolute: 9.46 × 1020 kg
Davyum is the fabricated name of a hypothetical element with the symbol Da and atomic number 146. Davyum was named in honor of Humphry Davy (1778–1829), who discovered numerous elements including several s-block elements and pioneered electrolysis. Davyum is the only transuranium element with name that does not end in '-ium,' because the main root ends in 'y.' This element is known in the scientific literature as unquadhexium (Uqh), eka-plutonium, or simply element 146. Davyum is the sixth member of the dumaside series, found in the third row of f-block (below samarium and plutonium); this element is located in the periodic table coordinate 6f6.
Unlike most metals, which are gray or silvery, davyum is a reddish pink (cerise) metal. But like other metals, davyum is ductile, malleable, and shows pink luster. Its molar mass is 4053⁄8 g/mol while its molar volume is 322⁄3 cm3/mol; dividing molar mass by molar volume yields a density of 122⁄5 g/cm3. It forms base centered orthorhombic crystals that transforms to monoclinic crystals at 141 K (−206°F).
Davyum displays ferromagnetism, a property only few other elements have, including nickel and iron. It means davyum is attracted to magnets and forms permanent magnet when externally applied by magnetic fields. When heated to above its Curie temperature of 477 K (398°F), it loses ferromagnetism. Above that temperature, davyum is paramagnetic, a property most elements exhibit including all of the neighboring elements.
Davyum melts, meaning it changes from solid to liquid in a process of liquification, at 1386 K (2036°F), which is about the temperature of molten lava. It boils at 3437 K (5727°F), meaning at that temperature its vapor pressure is equal to ambient pressure and liquid converts into gas in a process called gasification. Because differences of separations between atoms are much greater between liquid and gas than from solid to liquid, it requires much more energy to transform liquid to gas than from solid to liquid. It requires 356 kJ to transform one mole of liquid into gas while it requires just 15 kJ to transform one mole of solid into liquid. The amount of energy needed to heat one mole of davyum by one degree Fahrenheit is 41 joules.
Davyum has the atomic mass 405.36 daltons and has the atomic radius 136 picometers, similar to zinc's. Davyum is the first element filling the f-orbital after completing the g-orbital, and two of the missing electrons in the f-orbital are in the d-orbital. Electrons orbit the nucleus comprising mostly of neutrons but with overall positive charge due to protons.
Like every other element heavier than lead, davyum has no stable isotopes. The most stable isotope is 402Da with a half-life (t½) of 18.8 hours. It undergoes spontaneous fission, splitting into two or more lighter nuclei plus neutrons.
All of the remaining isotopes have half-lives less than 50 minutes while majority of these have half-lives less than 4 minutes. Every isotope undergo fission most of the times. The most stable metastable isotope of davyum is 407mHm (t½ = 4.30 minutes).
Due to the filled g-orbital and relativistic effectss, davyum doesn't really have eka-plutonium properties. The ionization energy is 40% greater than plutonium's. Davyum has oxidation states from +2 to +3 with +3 being more common. The metal resists corrosion, but it slowly corrodes in hot water and strong acids.
Davyum(III) oxide is a blue-green amorphous solid formed when the metal exposes to air at high temperatures. At the same time, davyum can also combine with nitrogen to form a red DaN. Davyum reacts most readily with halogens since they're the most reactive family of elements. Davyum halides are colorful: DaF2 (reddish orange), DaF3 (red), DaCl2 (sky blue), DaCl3 (navy blue), DaBr2 (orange), DaBr3 (dark brown), DaI2 (yellowish pink), and DaI3 (pale pinkish peach).
Davyum can form salts via reactions with acids, such as Da2(SO4)3, DaPO4, and DaBO3. This metal can form organic compounds called organodavyum.
Occurrence and synthesis Edit
It is almost certain that davyum 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 davyum 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 davyum in the universe by mass is 2.82 × 10−32, which amounts to 9.46 × 1020 kilograms or about the mass of Ceres worth of davyum.
To go along with other such civilizations, humans on Earth may eventually have the capability to synthesize davyum. To synthesize most stable isotopes of davyium, 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. Here's couple of example equations in the production of the most stable isotope, 402Da.