Symbol Da
Atomic number 146
Pronunciation /'dāv•ē•(y)üm/
Named after Humphry Davy
Name in Saurian Tuløim (Tu)
Systematic name Unquadhexium (Uqh)
Location on the periodic table
Period 8
Family Neodymium family
Series Dumaside series
Coordinate 6f4
Element above Davyum Uranium
Element left of Davyum Heisenbergium
Element right of Davyum Boltzmannium
Atomic properties
Subatomic particles 548
Atomic mass 405.3607 u, 673.1172 yg
Atomic radius 136 pm, 1.36 Å
Covalent radius 149 pm, 1.49 Å
van der Waals radius 182 pm, 1.82 Å
Nuclear properties
Nucleons 402 (146 p+, 256 no)
Nuclear ratio 1.75
Nuclear radius 8.82 fm
Half-life 188.41 μs
Decay mode Spontaneous fission
Decay product Various
Electronic properties
Electron notation 146-8-24
Electron configuration [Og] 5g18 6f4 7d2 8s2 8p2
Electrons per shell 2, 8, 18, 32, 50, 22, 10, 4
Oxidation states +1, +2, +3, +4, +6, +8, +10
(a mildly basic oxide)
Electronegativity 1.94
First ionization energy 816.2 kJ/mol, 8.459 eV
Electron affinity 83.5 kJ/mol, 0.866 eV
Physical properties
Bulk properties
Molar mass 405.361 g/mol
Molar volume 32.683 cm3/mol
Density 12.403 g/cm3
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
Magnetic ordering Ferromagnetic
Crystal structure Base-centered orthorhombic
Color Cerise
Phase Solid
Thermal properties
Melting point 1386.39 K, 2495.51°R
1113.24°C, 2035.84°F
Boiling point 3437.26 K, 6187.07°R
3164.11°C, 5727.40°F
Liquid range 2050.86 K, 3691.56°R
Liquid ratio 2.48
Triple point 1385.70 K, 2494.25°R
1112.55°C, 2034.58°F
@ 4.7163 Pa, 0.035375 torr
Critical point 8506.97 K, 15312.54°R
8233.82°C, 14852.87°F
@ 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)
Abundance in the universe
By mass Relative: 2.82 × 10−33
Absolute: 9.46 × 1019 kg
By atom 1.83 × 10−34

Davyum is the provisional non-systematic name of a theoretical 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's name does not end in '-ium,' because the main root ends in 'y.' This element is known in the scientific literature as unquadhexium (Uqh), eka-uranium, or simply element 146. Davyum is the fourth member of the dumaside series, found in the third row of f-block (below neodymium and uranium); this element is located in the periodic table coordinate 6f4.

Atomic properties Edit

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.

Isotopes Edit

Like every other element heavier than lead, davyum has no stable isotopes. The longest-lived isotope is 402Da with a half-life (t½) of 188 microseconds. It undergoes spontaneous fission, splitting into two or more lighter nuclei plus neutrons.

Da → 223
Fr + 141
Pr + 38 1

Every isotope undergo fission most of the times. The most stable metastable isotope of davyum is 407mHm (t½ = 4.30 minutes).

Chemical properties and compounds Edit

Due to the filled g-orbital and relativistic effects, davyum doesn't really have eka-uranium properties. The ionization energy is 37% greater than uranium's. Davyum has oxidation states from +1 to +10 with +8 being more common. The metal resists corrosion, but it slowly corrodes in hot water and strong acids.

Davyum(VIII) 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 DaN2 or a brown Da3N8. Davyum reacts most readily with halogens since they're the most reactive family of elements. Davyum halides are colorful: DaF8 (reddish orange), DaF10 (red), DaCl6 (sky blue), DaCl8 (navy blue), DaBr6 (orange), DaBr8 (dark brown), DaI6 (yellowish pink), and DaI8 (pale pinkish peach).

Davyum can form salts via reactions with acids, such as Da(SO4)4, Da(PO4)2, and Da(BO3)2. This metal can form organic compounds called organodavyum.

Physical properties Edit

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 40538 g/mol while its molar volume is 3223 cm3/mol; dividing molar mass by molar volume yields a density of 1225 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.

Occurrence Edit

It is almost certain that davyum 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, then davyum must be produced in stars, and then thrown out into space 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. An estimated abundance of davyum in the universe by mass is 2.82 × 10−33, which amounts to 9.46 × 1019 kilograms or about 10% the mass of Ceres worth of davyum.

Synthesis Edit

To synthesize most stable isotopes of davyum, 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, 402Da.

Tl + 159
Tb + 38 1
n → 402
Ds + 84
Kr + 28 1
n → 402
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
1 H He
2 Li Be B C N O F Ne
3 Na Mg Al Si P S Cl Ar
4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
5 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
6 Cs Ba La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
7 Fr Ra Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og
8 Nw G Ls Dm M T Dt Mw Pk By Bz Fn Dw To Pl Ah My Cv Fy Chd A Ed Ab Bu Du Sh Hb Da Bo Fa Av So Hr Wt Dr Le Vh Hk Ke Ap Vw Hu Fh Ma Kp Gb Bc Hi Kf Bn J Hm Bs Rs
9 Me Jf Ul Gr Mr Arm Hy Ch Do Ib Eg Af Bhz Me Zm Qtr Bhr Cy Gt Lp Pi Ix El Sv Sk Abr Ea Sp Wg Sl Jo Bl Et Ci Ht Bp Ud It Yh Jp Ha Vi Gk L Ko Ja Ph Gv Dc Bm Jf Km Of Lb
10 Io Ly Chy Dnk Hng Le Aus Et Tg Ck Mv Lg Uk Fp Gp Mq Mts Gm Pal Pc Jd Ie Ym Om Sd Ld Cy Mlt Tv Fj Wl So Kb Mh Tk Nr Sol Cld Vt Tr Id Em Mu Sy My Cor Mur Ber Trd Ged Svc Agl Dg Su Sh
11 Flk Sog Asc Trs Bsi Tks Bvg Uvg Fof Nku Atf Chd