Symbol Ke
Atomic number 157
Pronunciation /'kel•vin• üm/
Named after Lord Kelvin
Name in Saurian Bocladim (Bo)
Systematic name Unpentseptium (Ups)
Location on the periodic table
Group 3
Period 8
Family Scandium family
Series Kelvinide series
Coordinate 7d1
Element above Kelvinum Lawrencium
Element left of Kelvinum Hawkinium
Element right of Kelvinum Amperium
Atomic properties
Subatomic particles 604
Atomic mass 450.7414 u, 748.4736 yg
Atomic radius 122 pm, 1.22 Å
Covalent radius 138 pm, 1.38 Å
van der Waals radius 193 pm, 1.93 Å
Nuclear properties
Nucleons 447 (157 p+, 290 no)
Nuclear ratio 1.85
Nuclear radius 9.14 fm
Half-life 371.63 ms
Decay mode Spontaneous fission
Decay product Various
Electronic properties
Electron notation 157-8-24
Electron configuration [Og] 5g18 6f14 7d3 8s2 8p2
Electrons per shell 2, 8, 18, 32, 50, 32, 11, 4
Oxidation states −1, 0, +1, +2, +3, +4, +5, +6, +7
(a mildly acidic oxide)
Electronegativity 1.25
First ionization energy 453.2 kJ/mol, 4.697 eV
Electron affinity 41.1 kJ/mol, 0.426 eV
Physical properties
Bulk properties
Molar mass 450.741 g/mol
Molar volume 15.818 cm3/mol
Density 28.495 g/cm3
Atomic number density 1.34 × 1021 g−1
3.81 × 1022 cm−3
Average atomic separation 297 pm, 2.97 Å
Speed of sound 4106 m/s
Magnetic ordering Metamagnetic
Crystal structure Face-centered cubic
Color Blue
Phase Solid
Thermal properties
Melting point 1335.03 K, 2403.05°R
1061.88°C, 1943.38°F
Boiling point 2243.97 K, 4039.14°R
1970.82°C, 3579.47°F
Liquid range 908.94 K, 1636.08°R
Liquid ratio 1.68
Triple point 1334.83 K, 2402.69°R
1061.68°C, 1943.02°F
@ 4.1866 Pa, 0.031402 torr
Critical point 5350.14 K, 9630.26°R
5076.99°C, 9170.59°F
@ 416.4821 MPa, 4110.372 atm
Heat of fusion 13.309 kJ/mol
Heat of vaporization 252.256 kJ/mol
Heat capacity 0.05272 J/(g•K), 0.09490 J/(g•°R)
23.765 J/(mol•K), 42.777 J/(mol•°R)
Abundance in the universe
By mass Relative: 3.38 × 10−32
Absolute: 1.13 × 1021 kg
By atom 1.97 × 10−33

Kelvinum is the provisional non-systematic name of a theoretical element with the symbol Ke and atomic number 157. Kelvinum was named in honor of Lord Kelvin (1824–1907), who developed the thermodynamic temperature, thus the Kelvin scale. This element is known in the scientific literature as unpentseptium (Ups), dvi-lutetium, or simply element 157. Kelvinum which is the fifth d-block series of the periodic table, and is the heaviest member of the scandium family (below scandium, yttrium, lutetium, and lawrencium); this element is located in the periodic table coordinate 7d1.

Atomic properties Edit

Kelvinum has 157 protons, hence its atomic number, and 290 neutrons to make up the atomic nucleus, corresponding to its nucleus:proton ratio of 1.85 and mass number 447. In the space surrounding the nucleus, there are 8 energy levels where 157 electrons reside. As expected for the periodic table, there are three electrons in the 7d orbital. The atomic mass is 450.741 daltons, 99.98% of its mass makeup the nucleus.

Isotopes Edit

Like every other element heavier than lead, kelvinum has no stable isotopes. The longest-lived isotope is 447Ke with a fission half-life of 371.6 milliseconds.

Ke → 279
Bh + 120
Sn + 48 1
Ke → 247
Bk + 90
Zr + 40
Ca + 70 1

There are metastable isomers of kelvinum, the longest is 444m1Ke with a half-life of 4.31 minutes while 444m2Ke has a half-life of 3.08 minutes, which are 700 and 500 times longer than the most stable ground state isotope, respectively.

Chemical properties and compounds Edit

Like other members of the scandium family, +3 is the most stable oxidation state, due to occupying d-orbital containing three electrons. With its most stable state, kelvinum can form binary pnictides as well as sesquichalcides and trihalides, thus it is most stable as ions in solutions. Kelvinum can also form compounds with other oxidation states with maximum possible oxidation state is +7 and its minimum is −1, with the latter used to achieve full 7d3/2 suborbital.

Kelvinum forms ionic complex with oxygen, called kelvinate (KeO2−
), such as found in compounds molybdenum kelvinate (Mo(KeO2)2), iridium kelvinate (Ir2(KeO2)3), and nickel kelvinate (NiKeO2).

Examples of kelvinum pnictides are KeN (dark purple powder) and KeP (pale pink powder). Kelvinum sesquoxide (Ke2O3), is a green powder while kelvinum sesquisulfide (Ke2S3) is an orange crystalline solid. The trihalides are KeF3, KeCl3, KeBr3, and KeI3, which are all offwhite ionic salts. Other salts include Ke2(SO4)3 (yellow), KeO3Cl (sky blue), and Ke(NH2)3 (lavendar). The nonvalent compounds of kelvinum are Ke2(CO)10, Ke(SN)4, Ke3(PF3)7, Ke(NO)2, and Ke(OF2)2.

Kelvinum(VII) carbide (Ke4C7) is a light gray refractory solid with the melting point of 2610°C (4730°F). Kelvinum lewisium carbide (Ke6LeC5) has a much higher melting point at 7140°C (12885°F) and is superconducting below −85°C (−121°F). Its melting point is so high that Ke6LeC5 would still be solid if we put it on the surface of the Sun, whose temperature is 5505°C (9940°F).

Physical properties Edit

Kelvinum is a dense, vibrant blue metal that is shiny, malleable, and ductile. The metal is blue due to electrons oscillating between the orbitals in energies corresponding to the blue region of the electromagnetic spectrum, which is the same reason why gold is yellow. Kelvinum's density is 28.5 g/cm3, denser than the densest known naturally occurring element, osmium. Kelvinum is the only element on the 172-element periodic table that is metamagnetic, meaning the strength of magnetism suddenly becomes greater with small changes in externally applied magnetic field.

The melting and boiling points of kelvinum are 1335 K and 2244 K, respectively.

Occurrence Edit

It is almost certain that kelvinum 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 kelvinum in the universe by mass is 3.38 × 10−32, which amounts to 1.13 × 1021 kilograms.

Synthesis Edit

To synthesize most stable isotopes of kelvinum, 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, 447Ke.

U + 159
Tb + 50 1
n → 447
Cn + 103
Rh + 53 1
n → 447
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