Ununennium: the essentials
- Name: ununennium
- Symbol: Uue
- Atomic number: 119
- Relative atomic mass (Ar): [ ?]
- Standard state: presumably a solid or liquid at 298 K
- Appearance: unknown, but probably metallic and silvery white or grey in appearance
- Classification: Metallic
- Group in periodic table: 1
- Group name: Alkali metal
- Period in periodic table: 8
- Block in periodic table: s
- Shell structure: 18.104.22.168.22.214.171.124
- CAS Registry: 54846-86-5
Ununennium atoms have 119 electrons and the shell structure is 126.96.36.199.188.8.131.52. The ground state electronic configuration of neutral ununennium is [Og].8s1 (a guess based upon that of caesium and francium) and the term symbol of ununennium is 2S1/2.
Ununennium, also known as element 119 (or eka-francium), is the as yet unknown chemical element with atomic number 119 and symbol Uue. Ununennium and Uue are the temporary systematic IUPAC name and symbol, until a permanent name is decided upon. In the periodic table of the elements, it is expected to be an s-block element, an alkali metal, and the first element in the eighth period.
Ununennium is the first element that has not yet been synthesized. To date, all attempts to synthesize this element have been unsuccessful. Its position as the seventh alkali metal suggests that it would have similar properties to the alkali metals, lithium, sodium, potassium, rubidium, caesium, and francium; however, relativistic effects may cause some of its properties to differ from those expected from a straight application of periodic trends. For example, ununennium is expected to be less reactive than caesium and francium and be closer in behavior to potassium or rubidium, and while it should show the characteristic +1 oxidation state of the alkali metals, it is also predicted to show the +3 oxidation state unknown in any other alkali metal.
Ununennium: physical properties
- Density of solid: 3000 (predicted, other predictions 3700-3400)) kg m-3
- Molar volume: (no data) cm3
- Thermal conductivity: (no data) W m‑1 K‑1
Ununennium: heat properties
- Melting point: (no data) K
- Boiling point: (no data) K
- Enthalpy of fusion: 20.5 kJ mol-1
Ununennium: atom sizes
- Atomic radius (empirical): (no data) pm
- Molecular single bond covalent radius: (no data) ppm
- van der Waals radius: (no data) ppm
- Pauling electronegativity: (no data) (Pauling units)
- Allred Rochow electronegativity: (no data) (Pauling units)
- Mulliken-Jaffe electronegativity: (no data)
Ununennium: orbital properties
- First ionisation energy: 437 kJ mol‑1
- Second ionisation energy: (no data) kJ mol‑1
- Third ionisation energy: (no data) kJ mol‑1
- Universe: (no data) ppb by weight
- Crustal rocks: (no data) ppb by weight
- Human: (no data) ppb by weight
Ununennium: crystal structure
Ununennium: biological data
- Human abundance by weight: (no data) ppb by weight
Since element 119 is unknown, it has no biological role.
Reactions of ununennium as the element with air, water, halogens, acids, and bases where known.
Ununennium: binary compounds
Binary compounds with halogens (known as halides), oxygen (known as oxides), hydrogen (known as hydrides), and other compounds of ununennium where known.
Ununennium: compound properties
Bond strengths; lattice energies of ununennium halides, hydrides, oxides (where known); and reduction potentials where known.
Ununennium: historyUnunennium was discovered by (no claim for discovery made) in (no claim for discovery made) at (no claim for discovery made). Origin of name: temporary systematic IUPAC nomenclature.
Isolation: as this element is unknown it has never never been isolated.