Future of the Periodic Table under the Spotlight at Royal Society Lecture

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The history and future of the Periodic Table was the subject of the Royal Society of South Africa public lecture presented by Professor John Douglas Hey, Emeritus Professor of Physics and Senior Research Associate at UKZN. The lecture coincided with the 150^th anniversary of the original form of the Periodic Table constructed and published by Dmitri Ivanovich Mendeleev, Professor of Chemistry in Saint Petersburg, Russia.

Hey explained that the Periodic Table in its present form represents centuries of patient thought and investigation by a variety of scholars of many nations, including amateurs and professional scientists, people working alone and, more recently, members of large research teams provided with generous funding.

‘The original Periodic Table represented the collective knowledge at the time of the elements of which all known matter is constructed,’ said Hey. ‘It was formed on the basis of the scientific achievements of many researchers over a period spanning several thousand years, from the first hypothesis of the atom by the Greek philosopher Democritus, to the work of the early alchemists, through to chemists such as Antoine Lavoisier and John Dalton in the 18^th and 20^th centuries.’

He explained that, since 1869, the Periodic Table has been expanded from an initial 55 elements and 11 “guesses” to the present total of 118, with the completion of the 7^th period by the inclusion of the element Oganesson-118.

‘In effect this systematic classification of the elements in terms of chemical and physical properties represents the solution to what may be the most complex jigsaw puzzle ever assembled, and stands as a testimony to the benefits of international scientific co-operation, not only by famous people, but by many others less well known, both men and women of many nations, whose diligent work has contributed to the success of the undertaking,’ said Hey.

‘Indeed, all modern technology employed in micro-electronics, data processing, laser-based research and space research, for example, depends upon our knowledge of these elements.

‘Our ability to solve the present, most pressing problems of our planet, related to depletion of natural resources, environmental degradation and also space research and exploration, will depend upon our use of the information encapsulated within the Periodic Table,’ he said.

Hey argued that the natural question to ask today, given the fact that human endeavour has enlarged the number of elements from 94 (naturally occurring) to 118, is the extent to which one might anticipate the enlargement and future extension of the Periodic Table. 

‘What future synthesis of new elements might we expect to be carried out successfully?’ he asked.

After presenting an outline of key achievements in the journey covered by the Periodic Table to date, Hey concluded his lecture by speculating on this key question: ‘Might our successors in the future succeed in reaching a so-called “Island of Stability” of new, heavy elements, which could be harnessed for the construction of new materials at present unknown?’

Hey said that on the basis of our present knowledge and understanding of atomic physics and quantum mechanics, nuclear structure, and the intricacies of modern quantum field theory, the answer to this question is at present still open.

Professor Hey lectured at the University of Cape Town from 1974 to 1990. He was also an Alexander von Humboldt Research Fellow at Ruhr University, West Germany from 1988 to 1989 and worked as a Wissenschaftlicher Mitarbeiter at the Institut fuer Plasmaphysik, Forschungszentrum Juelich, Germany from 1991 to 1995. He joined UKZN in 1995 where he was a Professor of Physics until 2009. He is now an Honorary Lecturer at the School of Chemistry and Physics.

Words: Sally Frost

Photograph: Bheki Mthembu