Four new elements have been added to the periodic table, finally completing the table’s seventh row. The elements, discovered by scientists in Japan, Russia and America, are the first to be added to the table since 2011, when elements 114 and 116 were added.
The four were verified on 30th December 2015 by the US-based International Union of Pure and Applied Chemistry (IUPAC), the global organisation that governs chemical nomenclature, terminology and measurement.
IUPAC announced that a Russian-American team of scientists at the Joint Institute for Nuclear Research in Dubna and Lawrence Livermore National Laboratory in California had produced sufficient evidence to claim the discovery of elements 115, 117 and 118.
The body awarded credit for the discovery of element 113, which had also been claimed by the Russians and Americans, to a team of scientists from the Riken institute in Japan.
Researchers at Riken, said they are now planning to look to the unchartered territory of element 119 and beyond.
The elements, which currently bear placeholder names, will be officially named by the teams that discovered them in the coming months. Element 113 will be the first element to be named in Asia.
IUPAC has now initiated the process of formalising names and symbols for these elements temporarily named as ununtrium, (Uut element 113), ununpentium (Uup, element 115), ununseptium (Uus, element 117), and ununoctium (Uuo, element 118).”
The four new elements, all of which are synthetic, were discovered by slamming lighter nuclei into each other and tracking the following decay of the radioactive superheavy elements.
Like other superheavy elements that populate the end of the periodic table, they only exist for fractions of a second before decaying into other elements.
Naming of the Elements
New elements can be named after a mythological concept, a mineral, a place or country, a property or a scientist. The names have to be unique and maintain “historical and chemical
consistency”. This means a lot of “-iums”.
“They’re Latinising the name,” explains chemist Andrea Sella of University College London. “The most recent tradition has been to name them after places or after people.” The places chosen tend to be where the element was discovered or first manufactured. The Swedish village of Ytterby has managed to get four named after it (ytterbium, yttrium, erbium and terbium).
No-one has yet named an element after themselves but many elements are named in tribute to important scientists. Albert Einstein was given einsteinium. This can also be a way of righting the wrongs of the past. “Lise Meitner was really the chemist who spotted nuclear fission but she was never really recognised for it because she was Jewish and a woman,” says Sella. “To be able to give an element a name that reminds us of her is, I think, greatly important.”
The naming process isn’t quick. The scientists who discovered them will start things off by proposing a name to IUPAC to approve it. There is then a public review period of five months before the IUPAC council gives the final approval. Once it’s ready, the name is announced in the scientific journal Pure and Applied Chemistry.
Scientists sometimes get creative. Mythical names have proved popular. Promethium was named after a character from a Greek legend who stole fire from the gods to give to humans and was punished by being chained to rock so an eagle could feed on his liver for eternity. The name was meant to reflect the fact that synthesising new elements often requires sacrifice.
There is also hidden meaning in the table as in the naming of praseodymium and neodymium. They replaced didymium, wrongly thought to be an element but in fact a mixture of the two. “The reason I like them is because they’re called the green twin and the new twin,” says Sella. “Didymium was named after (the Greek for) twin but in fact it also means testicles.”
A physics professor is supporting a campaign calling for a newly discovered element to be named in memory of Motörhead front man Lemmy Kilmister.
Almost 83,000 heavy metal fans have signed a petition calling for one of four new elements to be named “Lemmium” in tribute to the 70-year-old rock star who died on December 28th 2015, two days after learning he had cancer. In order to meet the naming requirements of the IUPAC, a star has already been named Lemmy.