Symbol Ch
Atomic number 138
Pronunciation /'chad•wi•kē•(y)üm/
Named after James Chadwick
Name in Saurian Sxutnasbaim (Sx)
Systematic name Untrioctium (Uto)
Location on the periodic table
Period 8
Family Chadwickium family
Series Lavoiside series
Coordinate 5g18
Element left of Chadwickium Feynmanium
Element right of Chadwickium Astonium
Atomic properties
Subatomic particles 515
Atomic mass 380.1508 u, 631.2552 yg
Atomic radius 163 pm, 1.63 Å
Covalent radius 188 pm, 1.88 Å
van der Waals radius 171 pm, 1.71 Å
Nuclear properties
Nucleons 377 (138 p+, 239 no)
Nuclear ratio 1.73
Nuclear radius 8.63 fm
Half-life 16.185 h
Decay mode Cluster decay
Decay product 332Pl
Electronic properties
Electron notation 138-8-24
Electron configuration [Og] 5g12 6f3 7d1 8s2 8p2
Electrons per shell 2, 8, 18, 32, 44, 21, 9, 4
Oxidation states +4, +5
(a mildly basic oxide)
Electronegativity 1.48
First ionization energy 638.3 kJ/mol, 6.615 eV
Electron affinity 164.0 kJ/mol, 1.699 eV
Physical properties
Bulk properties
Molar mass 380.151 g/mol
Molar volume 52.933 cm3/mol
Density 7.182 g/cm3
Atomic number density 1.58 × 1021 g−1
1.14 × 1022 cm−3
Average atomic separation 445 pm, 4.45 Å
Speed of sound 4016 m/s
Magnetic ordering Paramagnetic
Crystal structure Face-centered cubic
Color Grayish white
Phase Solid
Thermal properties
Melting point 701.57 K, 1262.82°R
428.42°C, 803.15°F
Boiling point 1065.81 K, 1918.45°R
792.66°C, 1458.78°F
Liquid range 364.24 K, 655.63°R
Liquid ratio 1.52
Triple point 700.57 K, 1261.03°R
427.42°C, 801.36°F
@ 51.243 Pa, 0.38435 torr
Critical point 2798.51 K, 5037.31°R
2525.36°C, 4577.64°F
@ 605.2591 MPa, 5973.462 atm
Heat of fusion 6.668 kJ/mol
Heat of vaporization 118.528 kJ/mol
Heat capacity 0.05386 J/(g•K), 0.09695 J/(g•°R)
20.476 J/(mol•K), 36.856 J/(mol•°R)
Abundance in the universe
By mass Relative: 7.90 × 10−29
Absolute: 2.65 × 1024 kg
By atom 5.46 × 10−30

Chadwickium is the provisional non-systematic name of an undiscovered element with the symbol Ch and atomic number 138. Chadwickium was named in honor of James Chadwick (1891–1974), who discovered a neutron. This element is known in the scientific literature as untrioctium (Uto) or simply element 138. Chadwickium is the eighteenth element of the lavoiside series and located in the periodic table coordinate 5g18.

Atomic properties Edit

Chadwickium contains 377 nucleons, or particles that make up the nucleus comprising of protons and neutrons. Surrounding the nucleus, there are 8 shells and 24 orbitals. Assumably, the 5g orbital should be completed with 18 electrons, but actually there are twelve due to spin-orbit coupling due to relativistic effects. The six missing electrons in the 5g orbital are located in different orbitals in different shells, half are in a shell one beyond the 5g orbital at 6f orbital, while the rest are in two outermost shells, one in 7d and two in 8p.

Isotopes Edit

Like every other element heavier than lead, chadwickium has no stable isotopes. The longest-lived isotope is 377Ch with a half-life of 16 hours, undergoing cluster decay to 332Pl by emitting 10B and 20Ne plus 30 neutrons. Every remaining isotopes have half-lives under 30 minutes while majority of these under a minute. Chadwickium has meta states, the most stable is 376mCh (t½ = 40.5 seconds).

Chemical properties and compounds Edit

Chadwickium's oxidation states are +4 and +5. Ch4+ has the electron configuration of elemental chadwickium minus 8s2 and 8p2
, while Ch5+ has the electron configuration of Ch4+ minus 7d1. With the electronegativity of 1.48, it is little reactive. Due to Ch4+ being stable while O2− the most common oxygen ion and the most abundant supply of oxygen is O2, then that molecule simply bond to chadwickium to form ChO2 by exposure to air where O2 is abundant.

Chadwickium(IV) oxide (ChO2), can be made by simply putting the metal in place where there's air, literally anywhere but beyond Earth. This metal can even react with water to form chadwickium(IV) hydroxide (Ch(OH)4). This metal dissolves and reacts with strong acids such as hydrochloric acid to form chadwickium(IV) chloride (ChCl5) and sulfuric acid to form chadwickium sulfate (Ch2(SO4)5).

Physical properties Edit

Chadwickium is a silvery white metal that is lusterous, malleable, and ductile like most metals. Chadwickium has a density of 7.2 g/cm3 and its speed of sound is 4016 m/s. There are 11.4 sextillion atoms in one cubic centimeter of chadwickium and 320 septillion in one cubic foot.

Its melting point is 1263°R (702 K), and its boiling point is 1918°R (1066 K), making its liquid range of 655°R (364 K), which is narrow for a metal, slightly narrower than mercury's. Like temperature, the liquid state is only stable between a certain range of pressure, between the triple point and critical point. Liquid state would be nonexistent below the triple point while liquid state would be indistinguishable above the critical point. For the metal, the triple point is 1261°R (701 K), about the melting point, and a pressure of 51.24 Pa. Its critical point is 5037°R (2799 K) and 605.26 MPa.

Occurrence Edit

It is almost certain that chadwickium doesn't exist on Earth at all, but it is believe to barely exist somewhere in the universe due to its short lifetime. Every element heavier than iron can only naturally be produced by exploding stars. But it is virtually 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 chadwickium in the universe by mass is 7.90 × 10−29, which amounts to 2.65 × 1024 kilograms or about four times the mass of Mars worth of this element.

Synthesis Edit

To synthesize most stable isotopes of chadwickium, 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, 377Ch.

Po + 131
Xe + 38 1
n → 377
Lr + 80
Br + 32 1
n → 377
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 Ms 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 Ck Do Ib Eg Af Bhz Me Zm Qtr Bhr Cy Gt Lp Pi Ix El Sv Sk Abr Ea Sp Ws 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 10 Io Ly