Transactinide element is any of the 15 chemical elements that follow lawrencium (atomic number, 103) on the periodic table . An element’s atomic number equals the number of protons in the nucleus (core) of an atom of the element. In order of atomic number, the transactinide elements are rutherfordium (104), dubnium (105), seaborgium (106), bohrium (107), hassium (108), meitnerium (109), darmstadtium (110), roentgenium (111), copernicium (112), nihonium (113), flerovium (114), moscovium (115), livermorium (116), tennessine (117), and oganesson (118).
Transactinides are named for famous scientists or places important in their discovery. Before it is officially named, a newly discovered transactinide element is given a provisional name that comes from the Latin words for its atomic number. Traditionally, the scientific community has granted the discoverer of an element the right to suggest a permanent name. The suggestion is subject to acceptance by the International Union of Pure and Applied Chemistry (IUPAC).
All transactinides are radioactive, and there is no evidence that they exist in nature. They must be created in a device called a particle accelerator via nuclear fusion. In nuclear fusion , smaller atomic nuclei are forced to combine to make the nucleus of a heavier atom. In some cases, only a few atoms of a particular transactinide can be made at any one time. Some transactinide atoms are so unstable that they decay (break down) into smaller atoms and particles shortly after their creation, lasting a few seconds or less.
Transactinides with atomic numbers from 104 to 112 have an increasing number of electrons in a region called the 6d subshell. Transactinides with atomic numbers from 113 to 118 have an increasing number of electrons in a region called the 7p subshell. The number, energy, and arrangement of electrons in an atom determine the properties of an element, including how it reacts chemically with other atoms. Except for a few of the lighter transactinide elements, however, these atoms exist for such a short time that scientists do not know much about their chemistry.
