|Name in Saurian|| Bocladaim (Bo)|
|Systematic name|| Unpentseptium (Ups)|
|Location on the periodic table|
|Above element||Dubnium (105Db)|
|Previous element||Hawkinium (156Hk)|
|Next element||Amperium (158Ap)|
|450.7414 u, 748.4736 yg|
|Atomic radius||122 pm, 1.22 Å|
|Van der Waals radius||193 pm, 1.93 Å|
|s||447 (157 p+, 290 n0)|
|Electron configuration|| [Mc] 5g18 6f14 7d3 8s2 8p2|
2, 8, 18, 32, 50, 32, 11, 4
|Oxidation states|| −1, 0, +1, +2, +3, +4, +5, +6, +7|
(mildly acidic oxide)
|First ionization energy||453.2 kJ/mol, 4.697 eV|
|Electron affinity||41.1 kJ/mol, 0.426 eV|
|Covalent radius||138 pm, 1.38 Å|
|Molar mass||450.741 g/mol|
|Molar volume||15.818 cm3/mol|
|Atomic number density|| 1.34 × 1021 g−1|
3.81 × 1022 cm−3
|Average atomic separation||297 pm, 2.97 Å|
|Crystal structure||Face centered cubic|
|Melting point|| 1335.03 K, 2403.05°R|
|Boiling point|| 2243.97 K, 4039.14°R|
|Liquid range||908.94 , 1636.08|
|Triple point|| 1334.83 K, 2402.69°R|
@ 4.1866 Pa, 0.031402 torr
|Critical point|| 5350.14 K, 9630.26°R|
@ 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• ), 0.09490 J/(g• )|
23.765 J/(mol• ), 42.777 J/(mol• )
|Universe (by mass)|| Relative: 3.38 × 10−41|
Absolute: 1.13 × 1012 kg
Kelvinium is the fabricated name of a hypothetical element with the symbol Ke and atomic number 157. Kelvinium 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-tantalium, or simply element 157. Kelvinium is the heaviest member of the vanadium family (below vanadium, niobium, tantalum, and dubnium) and is the third member of the vanthoffide series; this element is located in the periodic table coordinate 7d3.
Kelvinium 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. Kelvinium's density is 28.5 g/cm3, denser than the densest known naturally occurring element, osmium. Kelvinium 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 kelvinium are considerably lower than lighter homologues due to dissimilar electron configurations caused by quantum and relativistic effects, it melts at 1335 K compared to 3122 K for dubnium and 3290 K for tantalum; it boils at 2244 K compared to 5731 K for tantalum and 6892 K for dubnium, making its liquid range lot narrower than these two above elements, just over 900 K range compared to between 3100–3300 K range for dubnium and tantalum. Due to its lower melting and boiling points, kelvinium requires less energy to melt or boil than the elements above it.
Kelvinium 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.
There are metastable isomers of kelvinium, the longest is 444m1Ke with a half-life of 4.31 minutes while 444m2Ke has a half-life of 3.08 minutes, which are 11500 and 8200 times longer than the most stable ground state isotope, respectively.
Like other members of the vanadium family, +3 is the most stable oxidation state, due to occupying d-orbital containing three electrons. With its most stable state, kelvinium can form binary pnictides as well as sesquichalcides and trihalides, thus it is most stable as ions in solutions. Kelvinium 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.
Kelvinium forms ionic complex with oxygen, called kelvinate (KeO2−
2), such as found in compounds molybdenum kelvinate (Mo(KeO2)2), iridium kelvinate (Ir2(KeO2)3), and nickel kelvinate (NiKeO2).
Examples of kelvinium pnictides are KeN (dark purple powder) and KeP (pale pink powder). Kelvinium sesquoxide (Ke2O3), is a green powder while kelvinium 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 kelvinium are Ke2(CO)10, Ke(SN)4, Ke3(PF3)7, Ke(NO)2, and Ke(OF2)2.
Kelvinium(VII) carbide (Ke4C7) is a light gray refractory solid with the melting point of 2610°C (4730°F). Kelvinium 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).
Occurrence and synthesis Edit
It is almost certain that kelvinium 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 kelvinium 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 kelvinium in the universe by mass is 3.38 × 10−41, which amounts to 1.13 × 1012 kilograms.
To go along with other such civilizations, humans on Earth may eventually have the capability to synthesize kelvinium. To synthesize most stable isotopes of kelvinium, 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 and even if nuclei of this element were produced would immediately decay due to its brief half-life. Here's couple of example equations in the production of the most stable isotope, 447Ke.