Symbol A
Atomic number 139
Pronunciation /'as•tōn•ē•(y)üm/
Named after Francis William Aston
Name in Saurian Ujkedaim (U)
Systematic name Untriennium (Ute)
Location on the periodic table
Period 8
Family Astonium family
Series Lavoiside series
Coordinate 5g19
Element left of Astonium Chadwickium
Element right of Astonium Edisonium
Atomic properties
Subatomic particles 519
Atomic mass 383.1759 u, 636.2785 yg
Atomic radius 142 pm, 1.42 Å
Covalent radius 164 pm, 1.64 Å
van der Waals radius 166 pm, 1.66 Å
Nuclear properties
Nucleons 380 (139 p+, 241 no)
Nuclear ratio 1.73
Nuclear radius 8.66 fm
Half-life 14.065 ms
Decay mode Spontaneous fission
Decay product Various
Electronic properties
Electron notation 139-8-24
Electron configuration [Og] 5g13 6f2 7d2 8p2 8s2
Electrons per shell 2, 8, 18, 32, 45, 20, 10, 4
Oxidation states +3, +4, +5, +6
(a mildly basic oxide)
Electronegativity 1.53
First ionization energy 665.2 kJ/mol, 6.895 eV
Electron affinity 108.3 kJ/mol, 1.122 eV
Physical properties
Bulk properties
Molar mass 383.176 g/mol
Molar volume 55.242 cm3/mol
Density 6.936 g/cm3
Atomic number density 1.57 × 1021 g−1
1.09 × 1022 cm−3
Average atomic separation 451 pm, 4.51 Å
Speed of sound 4419 m/s
Magnetic ordering Paramagnetic
Crystal structure Tetragonal
Color Brownish gray
Phase Solid
Thermal properties
Melting point 826.51 K, 1487.72°R
553.36°C, 1028.05°F
Boiling point 1475.66 K, 2656.19°R
1202.51°C, 2196.52°F
Liquid range 649.15 K, 1168.46°R
Liquid ratio 1.79
Triple point 826.48 K, 1487.67°R
553.33°C, 1028.00°F
@ 7.1855 μPa, 5.3896 × 10−8 torr
Critical point 2651.12 K, 4772.02°R
2377.97°C, 4312.35°F
@ 41.1465 MPa, 406.085 atm
Heat of fusion 8.013 kJ/mol
Heat of vaporization 150.529 kJ/mol
Heat capacity 0.05522 J/(g•K), 0.09939 J/(g•°R)
21.159 J/(mol•K), 38.086 J/(mol•°R)
Abundance in the universe
By mass Relative: 2.52 × 10−32
Absolute: 8.45 × 1020 kg
By atom 1.73 × 10−33

Astonium is the provisional non-systematic name of an undiscovered element with the symbol A and atomic number 139. Astonium was named in honor of Francis William Aston (1877–1945), who discovered isotopes and formulate the whole number rule of atomic masses. This element is known in the scientific literature as untriennium (Ute) or simply element 139. Astonium is the nineteenth element of the lavoiside series and located in the periodic table coordinate 5g19.

Atomic properties Edit

The atom contains 24 orbitals in 8 shells where 139 electrons reside. Its electronegativity, the ability to acquire electrons from another atom, is 1.53. Its atomic radius is 142 pm, similar to silver (144 pm). The nucleus contains 139 protons and 241 neutrons, adding these two would have a mass number 380 and dividing neutrons by protons would yield a nuclear ratio of 1.73. The mass of the nucleus is not exactly 380 daltons, but 383.10 daltons, because each nucleon have masses slightly over one dalton by less than 1%. However when taking electrons into account, the total mass of the atom is 383.18 daltons, which is just 0.02% greater than the mass of its nucleus.

Isotopes Edit

Like every other element heavier than lead, astonium has no stable isotopes. The longest-lived isotope is 380A with a brief half-life of 14 milliseconds. It undergoes spontaneous fission, splitting into two lighter nuclei plus neutrons like the example.

A → 184
Po + 159
Tb + 37 1

Astonium has meta states with much longer half-lives than ground state isotopes, including 381m1A (t½ = 5.1 min), 381m2A (t½ = 58.7 sec), 377mA (t½ = 19.7 sec), and 375mA (t½ = 3.8 sec).

Chemical properties and compounds Edit

Astonium is not very chemically active based on its electronegativity of 1.53 and first ionization energy 6.9 eV. It can slowly react with strong acids such as sulfuric acid and hydrochloric acid to form A(SO4)2 and ACl4, respectively. Astonium does not readily combine with oxygen from the air, but it tarnishes at moderate rate when the metal is heated to around the boiling point of water. In addition to +4 oxidation state in compounds just mentioned, the element also takes on a +3, +5, and +6 states. Astonium forms aqueous solution with A4+ (yellow-green) or A6+ (hot pink).

Astonium can form complex anions such as AO2−
and APS

Astonium(III) boride (AB) and astonium(III) diboride (AB2) are refractive binary compounds between astonium and boron. Astonium can form trihalides or pentahalides, such as AF5, ACl5, ABr3, and AI5. Astonium can form oxides when metal exposes to the oxygen-rich air for a while, it can either form A2O3 or A2O5, both are black powder or as brittle form covering the original shape of metal that can easily be scraped off. It can also form a nitride, A3N4, as well as sulfide, AS2, when combined together would result in A(SN)4 and astonium metal.

A3N4 + 2 AS2 → A(SN)4 + 4 A

Examples of organoastonium compounds are diphenylastonium (Ph2A) and astonium fructose (C6H8O6A).

Physical properties Edit

Astonium is a brownish gray metal that shows golden luster whose density is approaching 7 g/cm3, similar to zinc's. The crystals form tetragonal in the solid state at room temperature (25°C, 77°F), but transitions to face-centered cubic at 272°C (522°F). At room temperature, the atoms are separated by 4.51 Å (451 pm) on average. Heating the metal causes atoms to move further apart while cooling it causes atoms to move closer to each other.

Astonium melts at 553°C (1028°F) and boils at 1203°C (2197°F), corresponding to its liquid range of 649°C (1168°F). It requires one and a half dozen times more energy to boil this element than melting. Its triple point pressure is 7 micropascals, where all three phases of matter are equally stable in equilibrium at temperature few hundredth of a degree lower than its melting point at atmospheric pressure.

Occurrence Edit

It is almost certain that astonium 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. An estimated abundance of astonium in the universe by mass is 2.52 × 10−32, which amounts to 8.45 × 1020 kilograms.

Synthesis Edit

To synthesize most stable isotopes of astonium, 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, 380A.

Yb + 169
Tm + 37 1
n → 380
Bk + 98
Mo + 35 1
n → 380
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 Tn Og
8 Nw G Ls Dm Ms Ts Dt Mw Pk By Bz Fn Dw To Pl Ah My Cv Fy Ch 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 An Hy Ck Do Ib Eg Af Ln Jk Hl Bw Ri Cy Gt Lp Pi Ix El Sv Nm Abr Ea Sp Wash Sl Jo Bl Et Ci Ht Bp Ud It Yh Jp Ha Vi Gk L Ko Ja Ph Gv Dc Bm Jf Km Oc Lb