You Wait Ages for a Chemical Element, and Then… BINGO!!

A photograph of Kosuke Morita, the leader of the Riken team, posing with a board displaying the new atomic element 113 during a press conference in Wako, Saitama prefecture on 31 December 2015.Four Elements Come Along at Once…

Just like buses, it seems.  But even rarer and a damn sight more exciting to be honest.  Ooohoo!!!  Out with your old Science books!!  HeL-LOOooo elements 113… 115, 117 and 118!!

The latest additions to the Periodic Table of Elements were formally verified by the International Union of Pure and Applied Chemistry (IUPAC) and the International Union of Pure and Applied Physics (IUPAP) on 30 December 2015.

 

Element_113_Ununtrium_286_Metal_Periodic_TableElement 113

IUPAC awarded credit for the discovery of element 113 to a Japanese team at the RIKEN Institute

Known as eka-thallium or element 113, it was first reported to have been created in 2003 by the Joint Institute for Nuclear Research in Dubna, Russia, and in 2004 by a team of Japanese scientists at RIKEN.

In the periodic table, ‘Ununtrium‘ (Uut) is a p-block transactinide element.  Transactinides, or super-heavy elements, are the chemical elements with atomic numbers from 104 to 118.

A member of the 7th period, element 113 is placed in the boron group.  The boron group comprise the chemical elements in group 13 of the periodic table of elements.  The elements in the boron group are characterised by having three electrons in their outer energy levels (or valence layers).

‘Ununtrium’ has been calculated to have some similar properties to its lighter homologues: boron (B), aluminium (Al), gallium (Ga), indium (In) and thallium (Tl), although it has not been confirmed to behave as the heavier homologue to thallium in the boron group.  Unlike all the other p-block elements, it is predicted to show some transition metal character.

Ununtrium is a temporary name of the chemical element with atomic number 113, with temporary symbol Uut.  Element 113 is a synthetic element – one that was created in a laboratory, but is not found in nature.

Element 113 is extremely radioactive.  Its most stable known isotope, ununtrium-286, has a half-life of 20 seconds.

 

Ununpentium_Element_115Elements 115, 117 and 118

IUPAC also announced that a team of Russian and American researchers had provided sufficient evidence to claim the discovery of elements 115, 117 and 118.

Eka-bismuth aka element 115 was first created in 2003 by a team composed of Russian scientists at the JINR, and American scientists at the Lawrence Livermore National Laboratory.  ‘Ununpentium‘ was recognised as a new element.  About 100 atoms of it have been observed to date, all of which have been shown to have mass numbers from 287 to 290.

Ununseptium_Element_117Element 117, or eka-astatine, is the second-heaviest known element and penultimate element of the 7th period on the periodic table of the elements.  As of 2016, fifteen ‘ununseptium atoms have been observed: six when it was first synthesized in 2010, seven in 2012, and two in 2014.

Ununoctium_Element_118Last on the periodic table, eka-radon, or element 118, is a p-block element and the last one of the 7th period.  ‘Ununoctium‘ is currently the only synthetic member of group 18.  It has the highest atomic number and atomic mass of all the elements discovered so far.  Formerly thought to be a gas under normal conditions, element 118 is now predicted to be a solid due to relativistic effects.

 

A section of the Periodic Table complete with the four new chemical elements.The Periodic Table of Elements

In 1869, the first true iteration of the periodic table of elements was devised by Russian chemist Dmitri Mendeleev – as a way of illustrating the periodic trends in the properties of the then-known elements.  The periodic table is laid out in rows to illustrate recurring (periodic) trends in the chemical behaviour of the elements as their atomic number increases: a new row is begun when chemical behaviour begins to repeat, meaning that elements with similar behaviour fall into the same vertical columns.

A period 7 element is one of the chemical elements in the seventh row (or period) of the periodic table of the chemical elements.  The seventh period contains 32 elements, tied for the most with period 6, beginning with francium and ending with ununoctium, the heaviest element currently discovered.

‘Unun-trium’, ‘Unun-pentium’, ‘Unun-septium’ and ‘Unun-octium’… are the first chemical elements to be formally included to the periodic table since 2011, when elements 114 and 116 were added.

 

Overall, What’s an Element?

From atomic numbers 1 (hydrogen) to 118 (ununoctium)…

A chemical element or element is a chemical substance consisting of atoms having the same number of protons in their atomic nuclei (the same atomic number, Z).  One hundred and eighteen elements have been identified, of which the first 94 occur naturally on Earth, with the remaining 24 being synthetic elements.

A diagram showing the three isotopes of Hydrogen.There are 80 elements that have at least one stable isotope and there are 38 radioactive isotopes, which decay over time into other elements.  Iron is the most abundant element (by mass) making up the Earth, while oxygen is the most common element in the crust of the Earth.

The first 98 elements exist naturally, although some are found only in trace amounts and were initially discovered by synthesis in laboratories.  Chemical elements constitute approximately 15% of the matter in the universe – the remainder is dark matter, the composition of which is unknown…

A Periodic Table showing the cosmogenic origin of the elements.
Cosmogenic origin of the Elements in the Periodic Table  Source: Wikipedia

Elements with atomic numbers from 99 to 118 have only been synthesised, or claimed to be so, in laboratories.  Production of elements having higher atomic numbers is being pursued, with the question of how the periodic table may need to be modified to accommodate any such additions being a matter of ongoing debate.

Numerous synthetic radionuclides of naturally occurring elements have also been produced in laboratories.

Unun-trium Uut 113, Unun-pentium Uup 115, Unun-septium Uus 117, Unun-octium Uuo 118.

New chemical elements can be named after a mythological concept, a mineral, a place or country, a property or a scientist.  No-one has yet named an element after themselves, but many elements have been named in tribute to important scientists.  Albert Einstein was given einsteinium.

The names must be unique and maintain “historical and chemical consistency“.  In other words, this means a lot of “-iums”.

The process of naming new elements is not quick.  The scientific teams responsible for the discoveries have been invited to start proposing new names and two-letter symbols.  But it will be left to IUPAC to approve it – a special division of the US-based group has to accept the proposal.  This is followed by a public review period of five months before the IUPAC council gets the final approval.

Once ready, the permanent names and chemical symbols for the now-confirmed elements are announced in the scientific journal Pure and Applied Chemistry.

 

Whatever Next?

Ununennium (Uue) is the element with the lowest atomic number that has not yet been synthesized.  Also known as eka-francium or element 119, Ununennium is a hypothetical chemical element.  In the periodic table of the elements, it is expected to be an s-block element, an alkali metal, and the first element in the eighth period. But for now…

All elements have now been discovered or reportedly synthesized, including the four missing elements 113, 115, 117, and 118 that remained to be confirmed.  Around the World, your Science textbooks have just become out-of-date!