Periodic table's seventh row is finally complete: Four elements have been permanently added to plug the chart's gap

• New elements discovered by Russian, American and Japanese scientists
• Elements 113, 115, 117 and 118 are first to be added since 2011
• They are the missing pieces which complete the table's seventh row
• Element 113 is the first to be discovered and named by Asian scientists 

Chemists around the world have celebrated the New Year with the addition of four newly discovered chemical elements to the periodic table.

The new elements, which were verified by international bodies on 30 December and have been given temporary names, are the missing jigsaw pieces needed to complete the seventh row of the iconic table.

Teams of scientists from Japan, Russia and the US that uncovered the missing elements have now been invited to give permanent names to their new discoveries.

Professor Kosuke Morita (pictured) led a team of scientists that has been awarded the right to name a synthetic element they created, which will become element 113 on the periodic table

The new elements don't appear in nature, but are unstable reactive elements made in the laboratory. 

Although they were first discovered between 2003 to 2008, it took some years to verify and reproduce the results.

All discoveries have to be officially verified by a joint working group of two US-based bodies - the International Union of Pure and Applied Chemistry (IUPAC) and the International Union of Pure and Applied Physics (IUPAC). 

These groups are the guardians of new admissions to the table.

Elements 115, 117 and 118 were discovered through a collaborative effort between US and Russian scientists from the Joint Institute for Nuclear Research in Dubna, Russia, the Lawrence Livermore National Laboratory in California and Oak Ridge National Laboratory in Tennessee.

These elements have the temporary names and symbols of ununpentium (Uup), ununseptium (Uus) and ununoctium (Uuo).

Meanwhile element 113 or 'ununtrium' (Uut), was discovered by scientists at the Riken Institute in Japan, led by Professor Kosuke Morita.

The acceptance of the element by the international bodies makes it the first chemical element to be discovered and named by Asian scientists.

The Riken Institute said in a statement: 'IUPAC has announced that Morita's group will be given priority for the discovery of the new element, a privilege that includes the right to propose a name for it.'

At a press conference, Professor Morita told reporters: 'I feel grateful that the name will be included in the table for the first time after this recognition.'

President of the IUPAC, Dr Mark Cesa, added the organisation was 'pleased and honoured' to announce the new elements and to complete the seventh period of the table.

Dr Cesa added: 'We are excited about these new elements, and we thank the dedicated scientists who discovered them for their painstaking work, as well the members of the IUPAC/IUPAP Joint Working Party for completing their essential and critically important task.' 

Commenting on the nature of the four newest elements, chair of the IUPAC/IUPAP joint working group, Professor Paul Karol, said: 'A particular difficulty in establishing these new elements is that they decay into hitherto unknown isotopes of slightly lighter elements that also need to be unequivocally identified.'

He added: 'But in the future we hope to improve methods that can directly measure the atomic number, Z.'

The new elements take their place in the seventh row, or period, of the periodic table. 

The four are the first elements to be added to the table since elements 114 and 116 - Flevorium and Livermorium which were discovered in Russia and the US, respectively - were accepted by the IUPAC/IUPAP in June 2011.

Full reports from the IUPAC and IUPAP are expected to be published in the journal Pure and Applied Physics soon.