Tableau périodique des éléments chimiques et actinides

Uranium ($\mathrm{Z} = 92$) is known since 1789 and it remained the heaviest element of the periodic table until 1940. In 1925 all the stable or radioactive natural elements were known and assigned in this table, the latest being discovered that year being rhenium. Three boxes in the table remained empty ($\mathrm{Z}= 43$, 61 and 85) and despite the efforts of the chemists to fill them, the periodic table remained unchanged until 1937. After the discovery of artificial radioactivity in 1934 it was quickly understood that man-made elements could be produced and that the periodic table could be completed and extended beyond $\mathrm{Z} = 92$. The first synthetic element with $\mathrm{Z} 92$ was the neptunium. This article deals with the discovery and chemical identification of the first transuranic elements $\mathrm{Z} = 93$ to 96 and the following ones, up to $\mathrm{Z} =103$, and how they have been incorporated into the series of actinides