Isotopes of ununseptium
Encyclopedia
Ununseptium
(Uus) is the most-recently synthesized artificial element, and much of the data is hypothetical. As any artificial element, a standard atomic mass
cannot be given. Like all artificial elements, it has no stable isotope
s. The first (and so far only) isotope
s to be synthesized were 293Uus and 294Uus in 2009. The longer-lived isotope is 294Uus with a half-life
of 78 ms.
Ununseptium
Ununseptium is the temporary name of a superheavy artificial chemical element with temporary symbol Uus and atomic number 117. Six atoms were detected by a joint Russia–US collaboration at Dubna, Moscow Oblast, Russia, in 2009–10...
(Uus) is the most-recently synthesized artificial element, and much of the data is hypothetical. As any artificial element, 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...
s to be synthesized were 293Uus and 294Uus in 2009. The longer-lived isotope is 294Uus with 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 78 ms.
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 |
|---|---|---|---|---|---|---|---|
| 293Uus | 117 | 176 | 14 (+11, -4) ms | α Alpha decay Alpha decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle and thereby transforms into an atom with a mass number 4 less and atomic number 2 less... |
289Uup | ||
| 294Uus | 117 | 177 | 78 (+370, -36) ms | α | 290Uup |
External sources
- Isotope masses from Ame2003 Atomic Mass Evaluation: G. Audi, O. Bersillon, J. Blachot, A.H. Wapstra, The Nubase evaluation of nuclear and decay properties, Nucl. Phys. A729 (2003) 3-128.
- Isotopic compositions and standard atomic masses from Atomic Weights of the Elements: Review 2000 (IUPAC Technical Report). Pure Appl. Chem., Vol. 75, No. 6, pp. 683–800, (2003).