Transactinoids
As transactinides ( Latin trans beyond , transactinides beyond the actinides ) is called the chemical elements with atomic numbers from 104 follow the periodic table of the actinides . All transactinoids are also transuranic at the same time , since they have atomic numbers greater than those of uranium . Isotopes of all transactinoids up to and including atomic number 118 have been synthesized to date . All are radioactive and have very short half-lives ranging from nanoseconds to minutes.
List of transactinoids
The names of the first five transactinoids were the subject of the element naming controversy that was resolved in 1997. They are named after nuclear physicists or after locations that played a role in the synthesis of elements.
So far known transactinoids :
- 104 Rutherfordium , Rf (after Ernest Rutherford )
- 105 Dubnium , Db (after Dubna , the place of production)
- 106 Seaborgium , Sg (after Glenn T. Seaborg )
- 107 Bohrium , Bh (after Niels Bohr )
- 108 Hassium , Hs (after Hassia , Latin for Hesse , the state of production - at the GSI in Darmstadt )
- 109 Meitnerium , Mt (after Lise Meitner )
- 110 Darmstadtium , Ds (to Darmstadt , the place of production)
- 111 Roentgenium , Rg (after Wilhelm Conrad Röntgen )
- 112 Copernicium , Cn (after Nicolaus Copernicus )
- 113 Nihonium , Nh (after Nihon, Japan , the seat of the RIKEN Institute)
- 114 Flerovium , Fl (after Georgi Fljorow (English transcription Flerov ))
- 115 Moscovium , Mc (to Moscow )
- 116 Livermorium , Lv (after Lawrence Livermore National Laboratory , the place of production)
- 117 Tenness , Ts (after Tennessee , the seat of the Oak Ridge National Laboratory )
- 118 Oganesson , Og (after Juri Oganessian )
generation
The transactinoids can be generated by nuclear reactions . For example, a linear accelerator is used to accelerate lighter atomic nuclei and shoot at heavier ones.
By nuclear fusion is produced with a very low probability of a heavier element. For example, rutherfordium (element 104) can be formed from oxygen (element 8) and curium (element 96). Typical amounts that can be generated decrease from element to element from about one atom per minute (rutherfordium) to one atom in several days or weeks (element 116). Weighable quantities are therefore not available.
Chemical properties
Little is known about the chemical properties of the transactinoids because of their short half-lives and the small amounts that can be produced.
Nevertheless, some chemical experiments were carried out for characterization. The main question is whether the elements can be classified in the assumed groups of the periodic table. Due to the relativistic effect, it would be conceivable, for example, that element 112 could show behavior similar to noble gas, although formally element 118 is the next noble gas.
So far, however, none of the chemically investigated elements (104–108 and 112) has shown a deviation from group membership.
For concept formation
The transactinides are often referred to as "transactinides" (also in the specialist literature). Since, however, in general, the elements beyond actinium (atomic number 89) are not meant, but those beyond actinides , transactinides is the more precise term.