Periodic table with elements colored according to the half-life of their most stable isotope. All four new elements are extremely radioactive elements: the most stable isotope has a half-life less than several minutes.

The International Chemistry Union IUPAC have approved four new elements. This approval makes the seventh row of the periodic table complete.

The elements with atomic numbers 113, 115, 117 and 118 are the heaviest known members of the boron group, the nitrogen group, the halogens and noble gasses.


All are highly reactive with half-lives of up to half a second. The elements result from research done by teams in Japan, Russia, and the United States.

The next phase of the process is to name the elements and the scientists behind the discoveries have six months during which they are to suggest names and symbols. These are then to be approved by IUPAC department of inorganic chemistry. Both scientists and the public have a saying on the names before approval by the IUPAC General Assembly in 2017.

The first report of the synthesis of ununpentium came in August 2003 and was reported on February 2, 2004, in Physical Review C by a team composed of Russian scientists at the Joint Institute for Nuclear Research (JINR) in Dubna, and American scientists at the Lawrence Livermore National Laboratory. The team reported that they bombarded americium-243 with calcium-48 ions to produce four atoms of ununpentium.
Simulation of an accelerated calcium-48 ion about to collide with an americium-243 target atom.

They have been given temporary names, though, said Professor Jan Reedijk, President of the Inorganic Chemistry Division of IUPAC. The elements have been temporarily named as ununtrium, (Uut or element 113), ununpentium (Uup, element 115), ununseptium (Uus, element 117), and ununoctium (Uuo, element 118).


Since the periodic table is systematically built, there have been some gaps in the table and these gaps hint of elements that should exist. The elements are not “natural” in the sense of all being created in a laboratory setting. But with this announcement, all the gaps are now filled.

Discovery and Assignment of Elements with Atomic Numbers 113, 115, 117 and 118