Science

The Four Newest Elements in the Periodic Table Have Names

Say hello to nihonium, moscovium, tennessine and oganesson. If you dislike any of them, you’ve until November 2016 to appeal.

A dissolved isotope of berkelium used in the synthesis of tennessine (element 117). Credit: Wikimedia Commons

A dissolved isotope of berkelium used in the synthesis of tennessine (element 117). Credit: Wikimedia Commons

On June 8, the International Union for Pure and Applied Chemistry (IUPAC) announced the official names of four new elements. Their inclusion completes the seventh row of the Periodic Table of elements. Here’s all you need to know about them.

How come none of them are named Element McElementface?

As much as many of us would enjoy that, the IUPAC has some rules for how elements can be named, and an element isn’t named until the IUPAC names it. These are the rules, as spelled out on its website: new elements can be named for

  • A mythological concept or character
  • A mineral or similar substance
  • A place or geographical region
  • A property of the element
  • A scientist

And now that the new names have been publicised, IUPAC will wait for five months (until November 2016) to allow for any appeals or opposition before officially confirming them.

So what are the new elements like?

They’re all super-heavy – which means they have more than 104 protons in their nuclei. They were added to the Periodic Table in January 2016, to the seventh row, after the likes of bohrium, hassium and copernicium. And they’re all very radioactive; the most stable isotope of the one with 115 protons in its nucleus has a halflife of 220 milliseconds.

What are their names?

By the number of protons in their nucleus, i.e. their atomic number,

  • 113 – nihonium (Nh)
  • 115 – moscovium (Mc)
  • 117 – tennessine (Ts)
  • 118 – oganesson (Og)

The rationale behind the first three names is more apparent than that behind the fourth.

‘Nihon’ is one of Japan’s formal names for itself, and stands for ‘land of the rising sun’. Nihonium was discovered at the RIKEN Nishina Center for Accelerator-based Sciences, Wako. It is also officially the first transuranic element (i.e. whose nucleus is heavier than uranium’s) to be discovered in Asia.

The state of Moscow lends its name to moscovium because that’s where the Joint Institute for Nuclear Research, among the first to spot atoms of the element, is located (in the city of Dubna). Tennessine is derived from the region in the US where two of the institutes involved in the discovery of element 117 are located.

Oganesson, unlike the other three, is named for a person: the Russian scientist Yuri Oganessian. Its name, as well as tennessine’s, contravenes one of IUPAC’s own rules, that the names of all elements should end in -ium. Additionally, oganesson is also only the second time an element has been named for a person still living. The last time was seaborgium in 1997 – for Glenn Seaborg, the American chemist who discovered ten transuraniuc elements (including plutonium).

According to JINR, Oganessian is “widely known for his [work] in the field of nuclear physics, research on nuclear reactions, experiments on synthesis and investigation of the properties of new elements of [the] periodic table.” He leads the Flerov Laboratory of Nuclear Reactions at JINR – for which element 114, flerovium, is named.

Who came up with these names?

IUPAC invited the groups that first discovered the elements (and when) to propose names:

  • Nihonium – RIKEN Nishina Center for Accelerator based Sciences (2012)
  • Moscovium – Joint Institute for Nuclear Research (JINR), Dubna; Lawrence Berkeley National Laboratory, Berkeley; GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (2004-2015)
  • Tennessine – JINR; Oak Ridge National Laboratory, Tennessee; Lawrence Livermore National Laboratory, California; Research Institute of Atomic Reactors, Ulyanovsk (2010)
  • Oganesson – JINR (2006-2015)

Great. Where can I find them?

You can’t – not unless you’re in a lab researching these elements because they lead a fleeting existence. The most stable of the four is nihonium – whose most stable isotope in turn has a halflife of just 20 seconds. This means half the nuclei in a given sample of nihonium will radioactively decay in 20 seconds. The halflife of the most stable isotope of moscovium is 220 milliseconds; of tennessium is about 51 milliseconds; of oganesson, about 89 milliseconds.

Nuclear physicists find these elements (rather, their atoms) by bombarding heavier atoms with lighter atoms, or particles, or among the radioactive decay products of some nuclear reactions. For example, tennessine was discovered among the fallout of bombarding an isotope of berkelium with that of calcium using a particle accelerator at JINR. That berkelium isotope itself had a halflife of 330 days, and had to be used within six months of production.

How do you publicise the existence of a thing that exists for far shorter than the time it takes to speak its name?

Nuclear physicists have to perform repeated checks, seeing if they can reach the same conclusions every time. And it helps if another lab performing the same experiments also reaches the same conclusions. An example is what happened in the case of moscovium: JINR had announced the discovered of the element in 2004. However, the IUPAC was convinced only in 2013, when the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt came through with a validation of the 2004 claim.