Unbinilium

Unbinilium is a hypothetical (theoretical or imagined) element of the periodic table. It is also known as eka- radium.^[9] Its atomic number should be 120 and is has the symbol Ubn. The name Unbinilium and the symbol Ubn are temporary IUPAC names (meaning "one-two-zero-ium" in Latin). This name and symbol exists until a permanent name is decided and the element is discovered. It is expected to be a s-block element and an alkaline earth metal. It is the second element in the eighth period of the periodic table.^[10]

Unbinilium, ₀₀Ubn

Unbinilium
Pronunciation	/ˌuːnbaɪˈnɪliəm/ ​(OON-by-NIL-ee-əm)
Alternative names	element 120, eka-radium
Unbinilium in the periodic table
Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson Ra ↑ Ubn ↓ (Usq) ununennium ← unbinilium → unbiunium
Group	group 2 (alkaline earth metals)
Period	period 8 (theoretical, extended table)
Block	s-block
Electron configuration	[Og] 8s2 (predicted)[1]
Electrons per shell	2, 8, 18, 32, 32, 18, 8, 2 (predicted)
Physical properties
Phase at STP	solid (predicted)[1][2]
Melting point	953 K ​(680 °C, ​1256 °F) (predicted)[1]
Boiling point	1973 K ​(1700 °C, ​3092 °F) (predicted)[3]
Density (near r.t.)	7 g/cm3 (predicted)[1]
Heat of fusion	8.03–8.58 kJ/mol (extrapolated)[2]
Atomic properties
Oxidation states	(+1),[4] (+2), (+4), (+6) (predicted)[1][5]
Electronegativity	Pauling scale: 0.91 (predicted)[6]
Ionization energies	1st: 563.3 kJ/mol (predicted)[7] 2nd: 895–919 kJ/mol (extrapolated)[2]
Atomic radius	empirical: 200 pm (predicted)[1]
Covalent radius	206–210 pm (extrapolated)[2]
Other properties
Crystal structure	​body-centered cubic (bcc) (extrapolated)[8]
CAS Number	54143-58-7
History
Naming	IUPAC systematic element name
Isotopes of unbinilium v e
Template:infobox unbinilium isotopes does not exist
Category: Unbinilium view talk edit | references

This element has not been synthesized (obtained or discovered) yet. A German team at the GSI Helmholtz Centre for Heavy Ion Research attempted a research on 2011. It suggested a possible production of ²⁹⁹Ubn. But it couldn't be done. Attempts were planned by the Russian, Japanese, and French teams. Attempts were made in 2017-2020 and the experiments from the attempts showed that 8th period elements were difficult to synthesize. Unbinilium is expected to be the last element that can be synthesized through current technology.

Uses

As of 2025, it is still a theoretical element and has no uses.