As part of the ILL's college III seminars, Araceli LOPEZ-MARTENS was first invited in 2020 -- the year of the 150th anniversary of the Periodic Table of Chemical Elements -- but her presentation has unfortunately been postponed several time...
It is however now permanently available for you to watch and rewatch on Youtube! Enjoy the story of the periodic table and nuclear physics:
At the dawn of the 20th century, most scientists believed that matter was made up of atoms and that what distinguished the atoms of different elements was their mass. It was this mass that was used to classify the elements. The chemists of the time quickly became aware of periodicities in the chemical behaviour of certain elements that they tried to translate into tables, the most famous of which was that of the Russian chemist Dmitri Mendeleev. In Mendeleev's table, the elements were arranged by increasing atomic mass, some cells were left empty and the position of the elements was given by the letter Z, from the German word zahl (number). In this lecture, I will show how discoveries in nuclear physics have transformed our understanding of the atom, how they have given its true meaning to the periodic table and how they have completed the 7 periods of the periodic table up to the last known element: oganesson.