Isotopes of ununoctium
Encyclopedia
Ununoctium
(Uuo) is an artificial element, and thus a standard atomic mass
cannot be given. Like all artificial elements, it has no stable isotope
s. The first (and so far only) isotope
to be synthesized was 294Uuo in 2006. All data is hypothetical. Its sole known isotope has a half-life
of 890 microseconds.
than the synthesized isotope 294Uuo, most likely 293Uuo, 295Uuo, 296Uuo, 297Uuo, 298Uuo, 300Uuo and 302Uuo. Of these, 297Uuo, might provide the best chances for obtaining longer-lived nuclei, and thus might become the focus of future work with this element. Some isotopes with much more neutrons, such as some located around 313Uuo, could also provide longer-lived nuclei.
DNS = Di-nuclear system ; σ = cross section
Ununoctium
Ununoctium is the temporary IUPAC name for the transactinide element having the atomic number 118 and temporary element symbol Uuo. It is also known as eka-radon or element 118, and on the periodic table of the elements it is a p-block element and the last one of the 7th period. Ununoctium is...
(Uuo) is an artificial element, and thus a standard atomic mass
Atomic mass
The atomic mass is the mass of a specific isotope, most often expressed in unified atomic mass units. The atomic mass is the total mass of protons, neutrons and electrons in a single atom....
cannot be given. Like all artificial elements, it has no stable isotope
Stable isotope
Stable isotopes are chemical isotopes that may or may not be radioactive, but if radioactive, have half-lives too long to be measured.Only 90 nuclides from the first 40 elements are energetically stable to any kind of decay save proton decay, in theory...
s. The first (and so far only) isotope
Isotope
Isotopes are variants of atoms of a particular chemical element, which have differing numbers of neutrons. Atoms of a particular element by definition must contain the same number of protons but may have a distinct number of neutrons which differs from atom to atom, without changing the designation...
to be synthesized was 294Uuo in 2006. All data is hypothetical. Its sole known isotope has a half-life
Half-life
Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...
of 890 microseconds.
Table
| nuclide symbol |
Z(p Proton The proton is a subatomic particle with the symbol or and a positive electric charge of 1 elementary charge. One or more protons are present in the nucleus of each atom, along with neutrons. The number of protons in each atom is its atomic number.... ) |
N(n Neutron The neutron is a subatomic hadron particle which has the symbol or , no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen, nuclei of atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of... ) |
isotopic mass (u) |
half-life | decay mode(s) | daughter isotope(s) |
nuclear spin |
|---|---|---|---|---|---|---|---|
| 294Uuo | 118 | 176 | 890 µs | α | 290Uuh |
Theoretical
Theoretical calculations done on the synthetic pathways for, and the half-life of, other isotopes have shown that some could be slightly more stableStable isotope
Stable isotopes are chemical isotopes that may or may not be radioactive, but if radioactive, have half-lives too long to be measured.Only 90 nuclides from the first 40 elements are energetically stable to any kind of decay save proton decay, in theory...
than the synthesized isotope 294Uuo, most likely 293Uuo, 295Uuo, 296Uuo, 297Uuo, 298Uuo, 300Uuo and 302Uuo. Of these, 297Uuo, might provide the best chances for obtaining longer-lived nuclei, and thus might become the focus of future work with this element. Some isotopes with much more neutrons, such as some located around 313Uuo, could also provide longer-lived nuclei.
Target-projectile combinations leading to Z=118 compound nuclei
The below table contains various combinations of targets and projectiles which could be used to form compound nuclei with Z=118.| Target | Projectile | CN | Attempt result |
|---|---|---|---|
| 208Pb | 86Kr | 294118 | |
| 232Th | 64Ni | 296118 | |
| 238U | 58Fe | 296118 | |
| 244Pu | 54Cr | 298118 | |
| 248Cm | 50Ti | 298118 | |
| 249Cf | 48Ca | 297118 |
Theoretical calculations on evaporation cross sections
The below table contains various targets-projectile combinations for which calculations have provided estimates for cross section yields from various neutron evaporation channels. The channel with the highest expected yield is given.DNS = Di-nuclear system ; σ = cross section
| Target | Projectile | CN | Channel (product) | σ max | Model | Ref |
|---|---|---|---|---|---|---|
| 208Pb | 86Kr | 294Uuo | 1n (293Uuo) | 0.1 pb | DNS | |
| 208Pb | 85Kr | 293Uuo | 1n (292Uuo) | 0.18 pb | DNS | |
| 252Cf | 48Ca | 300Uuo | 3n (297Uuo) | 1.2 pb | DNS | |
| 251Cf | 48Ca | 299Uuo | 3n (296Uuo) | 1.2 pb | DNS | |
| 249Cf | 48Ca | 297Uuo | 3n (294Uuo) | 0.3 pb | DNS |