- meit·ner·i·um mīt-'nir-ē-əm, -'ner- n a short-lived radioactive element that is artificially produced symbol Mt see element (table)Meit·ner 'mīt-nər Lise (1878-1968)German physicist. One of the first women to pursue a career in physics, Meitner received a PhD in the subject from the University of Vienna before being hired by Max Planck as an assistant at the Institute for Theoretical Physics at the University of Berlin. Beginning in 1918, she was head of the physics department at Berlin's Kaiser-Wilhelm Institut. With German physical chemist Otto Hahn, Meitner discovered an isotope of protactinium, the parent element of actinium, in 1918. With Hahn and Otto von Baeyer, she studied beta emissions from thorium, radium, and uranium, while conducting her own studies on the range of radioactive particles. Forced in 1938 to flee Berlin for Stockholm, she assumed a post at the Nobel Institute. With physicist O. R. Frisch, she became the first to realize that recent experiments by Hahn and others in which uranium had been bombarded with neutrons had resulted in the splitting of the uranium nucleus into two nuclei of smaller masses accompanied by the release of a massive amount of energy. In a 1939 paper they introduced the term fission for this nuclear process. After 1947 Meitner did her research at Sweden's Royal Institute for Technology and a laboratory at the Royal Academy for Engineering Sciences. In 1997 the International Union of Pure and Applied Chemistry formally approved meitnerium as the name for element 109.
Medical dictionary. 2011.
Look at other dictionaries:
Meitnerium — Meitnérium Pour les articles homonymes, voir Mt. Meitnérium … Wikipédia en Français
meitnerium — [mīt nir′ē əm] n. 〚ModL, after MEITNER Lise + IUM〛 a radioactive chemical element with a very short half life: a transactinide produced by bombarding bismuth with high energy nuclear particles: symbol, Mt; at. no., 109: see the periodic table of… … Universalium
meitnerium — ● meitnerium nom masculin (de L. Meitner, nom propre) Élément chimique artificiel (Mt), de numéro atomique 109 et de masse atomique voisine de 268 … Encyclopédie Universelle
meitnerium — Symbol: Mt Atomic number: 109 Atomic weight: (266) Half life of approximately 5ms. The creation of this element demonstrated that fusion techniques could indeed be used to make new, heavy nuclei. Made and identified by physicists of the Heavy Ion … Elements of periodic system
meitnerium — [mīt nir′ē əm] n. [ModL, after MEITNER Lise + IUM] a radioactive chemical element with a very short half life: a transactinide produced by bombarding bismuth with high energy nuclear particles: symbol, Mt; at. no., 109: see the periodic table of… … English World dictionary
Meitnerium — hassium ← meitnerium → darmstadtium Ir ↑ Mt ↓ (Upe) … Wikipedia
Meitnérium — Pour les articles homonymes, voir Mt. Meitnérium Hassium ← Meitnérium → … Wikipédia en Français
Meitnerium — Eigenschaften … Deutsch Wikipedia
Meitnerium — meitneris statusas T sritis fizika atitikmenys: angl. meitnerium vok. Meitnerium, n rus. мейтнерий, m pranc. meitnerium, m … Fizikos terminų žodynas
Meitnerium — Meit|ne|ri|um [nach der österr. Physikerin L. Meitner (1878–1968); ↑ ium (1)], das; s; Symbol: Mt; früherer systematischer Name: Unnilennium (Une): nur künstlich herstellbares, radioaktives chem. Element (Transactinid) aus Gruppe 9 des… … Universal-Lexikon