Nobel Prize in Chemistry
| 1951 | EDWIN MATTISON MC MILLAN for their discoveries in the chemistry of the transuranium elements | The discovery of elements heavier than uraniumUranium, which is the 92nd element (i.e. an atom with a nucleus containing 92 protons) is the heaviest of all naturally occurring elements on Earth. However, by producing nuclear reactions, Man is now able to create elements heavier than uranium. This quest for new elements has made great advances since the research work of these two Nobel prize-winners. In particular, the nuclear models developed since then predict a "stability island" in the vicinity of elements 114, 120 or 126. These are the so-called super-heavy elements. In recent years, the discoveries of elements 112, 113, 114, 115 and 116 were announced in succession. The most recently known element (which has been produced by several laboratories, and has been confirmed and named by the relevant international commission) is Darmstadtium, or element 110, whereas the name proposed today for element 111 is Roentgenium. Since GANIL now has sufficiently strong particle beams available, it has only a small participation in this race for superheavy elements. |
| 1944 | OTTO HAHNfor his discovery of the fission of heavy nuclei | Fission of heavy atomic nucleiFission is the breaking up of an atomic nucleus into two smaller fragments. Still today, this phenomenon is studied intensively, both in theory and by experiment. Recently, experiments carried out at GANIL demonstrated that the durations of fission reactions were much longer than had been previously suggested. These durations, which are long for atomic nuclei, seem however infinitely short for humans, since they are of the order of a billionth of a billionth of a second (i.e. from 10-16 to 10‑19 s) |
| 1935 | FRÉDÉRIC JOLIOT | Synthesis of new radioactive elements
These two Nobel prize winners may be credited as having been the founders of research on artificial nuclei. Such nuclei, which are said to be exotic when they do not occur naturally on Earth, are now synthesized in large numbers in laboratories such as those at GANIL. The new SPIRAL facility at GANIL even allows the exotic nuclei produced during nuclear reactions to be accelerated into beams. |
| 1934 |
HAROLD CLAYTON UREYfor his discovery of heavy hydrogen | Discovery of deuterium` It is now known that the hydrogen nucleus, which is the first and lightest element, usually contains only one particle, called the proton. The proton has a positive charge, opposite to that of the electron, which is negative. The hydrogen atom is electrically neutral, as it has a nucleus with a single proton, and one orbiting electron. Deuterium was discovered in 1932 by Sir Chadwick. It is a hydrogen atom whose nucleus contains, in addition to its single proton, a neutron, which is a neutral particle and also the proton’s twin brother, Two nuclei of the same element always have the same numbers of protons. For an atom to be neutral, it must contain as many negatively charged electrons as there are oppositely charged protons. Thus, the number of electrons is equal to the number of protons. This number is the atomic number. Conversely, the number of neutrons in atoms of a given element can vary, and thereby defines an isotope. Deuterium and hydrogen are two isotopes of the same element. Teams at GANIL recently contributed to the discovery of a "heavy" isotope of hydrogen, containing 4 neutrons. This hydrogen 5 was dubbed “Pentium” by some journalists! |
| 1921 | FREDERICK SODDYfor his contributions to our knowledge of the chemistry of radioactive substances, and his investigations into the origin and nature of isotopes | Chemistry of radioactive substances, and the origin and nature of isotopesBy studying radioactivity, Soddy was the first to understand that two atoms of the same element, i.e. two atoms having the same chemical properties, could have different masses. He called these two atoms located at the same position in the periodic table of elements isotopes (from Greek "isos", equal, and "topos", place). It is now known that two nuclei of the same element always have the same number of protons. For an atom to be neutral, it must contain as many electrons as there are protons of opposite charge. Thus, the number of electrons is equal to the number of protons. This number corresponds to the rank of the element in the periodic table, and is the atomic number, which defines the element. Conversely, the number of neutrons in atoms of a given element can vary, thus defining a specific isotope. Since the mass of an atom is given by the numbers of neutrons and protons, two different isotopes of the same element do not have the same mass. Since the neutron was only discovered in 1932 by Sir Chadwick, Soddy could obviously not explain this difference. He only observed that the masses of two atoms of the same element could be different. Today, the synthesis of new isotopes and the study of their properties is still a major research topic in nuclear physics. On Earth, approximately 250 isotopes can be found. 2000 isotopes that do not occur naturally on Earth have been synthesized to this day. Several thousands of these still need to be discovered and studied. |
| 1911 | MARIE CURIE, née Marie Sklodowska,in recognition of her services to the advancement of chemistry by the discovery of the elements radium and polonium, by the isolation of radium and the study of the nature and compounds of this remarkable element | Discovery and chemistry of radium and polonium
Discovering new elements and studying their chemical and physical properties, in particular their radioactivity, remains an important topic in nuclear research, which is nowadays focused on very heavy and super-heavy elements. |
