Welcoming new chemical elements: nihonium, moscovium, tennessine and oganesson

Every once in a time, the IUPAC (the International Union of Pure and Applied Chemistry) annonces names of new chemical elements. And we have today four new guys.

Although I am a physicist, I have worked during almost 10 years in a multidisciplinary laboratory with a large chemistry department. As a result, I followed, as an amateur, research and discoveries in chemistry. And even if I am not anymore working in this laboratory, I am still receiving news that I am happy to share.

Recently, I noticed an announcement from the IUPAC about naming new elements. Several research groups around the world are indeed working on experiments allowing to create and discover new superheavy elements.

As soon as reports that claim for a discovery are approved, the IUPAC invites the discoverer to propose names. And approval of course requires independent confirmation of the results.

_{[image credits: shutterstock]}

The first thing that excited me with the IUPAC announcement is that it was discussing the naming of the elements 113, 115, 117 and 118. Bringing back to my memory my teenager time, this actually means that I need to mentally complete the Mendeleev table I have in mind by several extra boxes.

As a second step, I have quickly investigated how names for new elements are chosen. Traditions are important, and they enforce the names of the elements to be connected to either a place or a scientist. In addition, the ending of the name (-ium, -on or -ine) is imposed to maintain chemical and historical consistency.

---

Element 113 - Nihionium

The JINR laboratory in Dubna (Russia) first claimed the discovery of this element in 2003, but the claim was not supported by any previous data. Their experimental setup indeed involved many new (heavier) elements at the same time, which made the results troublesome. Further data was hence needed.

This element was rediscovered on year later at the RIKEN laboratory in Japan. However this time again, data was not good enough to meet the criteria for a discovery.

One indeed needed to wait for the results of RIKEN experiments from 2012 to get enough confidence on the results. Nihonium was here prepared by bombarding a bismuth target with zinc. This experiment actually yielded the element name: nihon means Japan in Japanese (literally translated as the Land of the Rising Sun).

This is also the first time in history an Asian team was allowed to name an element.

---

Element 115 - Moscovium

This element was discovered by a joint team of Russian and American scientists in 2003, in the JINR laboratory in Dubna (the same as above), thanks to the contributions several US teams (Oak Ridge National Laboratory, Lawrence Livermore National Laboratory and Vanderbilt University to name them).

Moscovium was produced by bombarding an americium target with calcium ions. As a results, four atoms of moscovium were produced, decaying into nihonium (see above, it is the same experiment we are talking about). The problem is that no existing data was able to confirm these claims.

Since the confidence in the results was not large enough, one consequently needed to wait for an experimental confirmation... 10 years later.

As a result, the IUPAC recognized the moscovium element at the end of 2015, and the Russian-American team named it moscovium in the honor of the region of Moscow where the JINR laboratory is located.

---

Element 117 - Tennessine

The same Russian-American team which I discussed above has also discovered the element 117. The story here is more complicated as the proposal to produce this element required berkelium which was very costly to produce. Tennessine was indeed planned to be produced from the bombardment of a berkelium target with calcium.

The key event leading to a change was the starting of the production of californium for the US oil industry, from which berkelium could be extracted. After being purified, the berkelium was quickly (its lifetime is slightly less than a year, which leaves not much time to act) sent to Dubna for the production of Tennessine.

Funnily enough, the berkelium traveled 5 times within the US and Russia due to missing paperwork… But in 2010, the experiment happened and the tennessine was discovered. We have however had to wait a little, as the discovery was only confirmed in 2011-2012 and 2014 by both the same group and an independent research group from Germany.

The IUPAC recognized the element in December 2015, and the name was given as a recognition of the contribution of the Tennessee region to the production of superheavy elements. The Oak Ridge laboratory and the Vanderbilt university are indeed both located in this region.

---

Element 118 - Oganesson

The same American-Russian team as above is also responsible for the discovery of the element 118 (they are really working hard on superheavy nuclei). It is the element with the highest atomic element known today and it has been produced by the bombardment of a californium target with calcium ions.

Calcium-48 is the lightest near-stable nucleus with an important neutron excess: 20 protons and 28 neutrons. This is why it appears everywhere in this post.

The discovery was first claimed in 2006, but one had then to wait for the confirmation of the discovery. As all noble gazes, the ending of the element is in -on, and the name has been given in honour of the professor Yuri Oganessian who contributed significantly to the discoveries of superheavy nuclei. He is indeed part of the collaboration who discovered all elements from 114 to 118.

---

SOURCES

• The IUPAC announcement.
• Discovery of the nihonium.
• Discovery of the moscovium.
• Discovery of the tennessine.
• Discovery of the oganesson.
• A bunch of wikipedia pages: nihonium, moscovium, tennessine and oganesson.

_{And now I have a chemistry blog entry ^^}