MILESTONES IN CHEMISTRY

Marco Fontani

Gustave Bémont and the “doom” of -workers MARCO FONTANI Università degli Studi di Firenze, department of Chemistry “Hugo Schiff”, Via della Lastruccia, 13, Sesto F.no Firenze, 50019, Italy

isotopes of radium are radioactive; the element is used and ABSTRACT: While in Germany the government was planning handled in the form of radium or and to completely phase out nuclear power by 2021, Italy practically never in the metallic state. – after banning it for two decades – on February 24th Radium is a decay product of uranium and is, therefore, found 2009 became the latest EU country to embark on a in all uranium-bearing ores. One ton of pitchblende yields one new wave of nuclear energy development. Prime seventh of a gram of radium. It was isolated by Marie Curie Minister Silvio Berlusconi (b. 1936) and French President née Skl/odowska (1867-1934), her husband Pierre Curie (1859- Nicolas Sarkozy (b. 1955) signed an agreement to build 1906) and Gustave Bémont at the very end of XIXth century from at least four new nuclear plants in Italy, the intention pitchblende coming from North Bohemia, around Joachimsthal being to have the first one in operation by 2021. (now Jáchymov) in the former Austro-Hungarian Empire. For some people “nuclear energy” would represent a The Curies announced their discovery (1) to the French dream but for others a nightmare. In these challenging Academy of Sciences on 26 December 1898. Twelve years times where all industrialised countries are looking for new later, in 1910 Madame Pierre Curie and André Debierne energy sources, nuclear power – which has over a half (1874-1949) announced the isolation of metallic radium (2). century of history - is coming back into the limelight. In The following year, this result was crowned with a second this context it is worth refreshing our memory by recalling Nobel prize for Marie Curie, but no recognition for her some figures in the field of the radiochemistry; personages collaborator. Radium isolation in the metallic state, gave the who, with their discoveries, have opened the way for the proof that radioactive bodies were true and lawful elements. exploitation of the atom and for unfathomable reasons On the other hand malicious gossip reported that “the autumn have fallen totally into oblivion. One of them bears the 1911 announcement of the Nobel prize” arrived just in time to name of Gustave Bémont. hush up rumours about a relationship between Pierre Curie’s widow and Paul Langevin (1872-1946) – a brilliant former pupil of Pierre Curie – who was unhappily married (3) to Emma RADIUM: 100 YEARS AFTER ITS ISOLATION IN THE METALLIC STATE Jeanne Desfosses (b. 1874), with four children.

The heaviest of the alkaline earth metals, radium, is intensely radioactive and resembles in its chemical behaviour. This metal is found in tiny quantities in the uranium ore pitchblende, and various other uranium minerals. Radium preparations are remarkable for maintaining themselves at a higher temperature than their surroundings, and for their radiations, which are of three kinds: alpha particles, beta particles, and gamma rays. Some of the few practical uses of radium are derived from its radioactive properties. More recently discovered radioisotopes, such as 60Co and 137Cs, are replacing radium in even these limited uses because several of these isotopes are more powerful emitters, safer to handle, and available in more concentrated form. Radium does have some commercial and industrial uses. Radium bromide is the most important radium compound and it is used as a source of alpha - rays for the localized treatment of a few types of cancer. Small amounts of radium were used in the production of luminous paint, clock dials, doorknobs, and other objects, to make them visible in the dark. In industry radium sulphate is used in radiographic testing instruments to detect flaws in metals. Another industrial use is to mix radium and beryllium to obtain a source of neutrons, to geo-physically prospect for petroleum. All 3