In 1913, English physicist Henry Moseley established an elegant method for 'counting' the elements. Soon afterwards, it became clear that there were precisely seven elements missing from the periodic table-those that had yet to be isolated among the 92 naturally occurring elements from hydrogen (#1) to uranium (#92). In A Tale of Seven Elements, Eric Scerri will present the discovery of those seven elements, five of which are radioactive and three or possibly four of were first isolated by women. The book covers a period roughly spanning the two world wars, beginning with the discovery of protactinium in 1917 and ending with that of promethium in 1945. In some cases, the state of war directly influenced attempts to isolate some of the seven elements-this is true of protactinium, when, in 1916, its discoverer, Lise Meitner, wrote of the problems she encountered in purchasing even the most basic items of laboratory equipment. During the second war, the discovery of nuclear fission, also by Meitner and her associates, quickly led to the development of the nuclear weapons program and the associated technologies of particle accelerators. Clearly, scientific discoveries occur within a social and political context and the discovery of the seven elements is no exception. This book draws together for the first time the fascinating stories of the discoveries of these seven elements, placing them in historical context.