from The American Heritage® Dictionary of the English Language, 5th Edition.
- noun A radioactive metallic element, occurring naturally in small quantities as a product of radium disintegration and produced synthetically by bombarding bismuth or lead with neutrons. Most isotopes decay by alpha-particle emission; the most stable are Po-208 and Po-209, with half-lives of 2.9 years and 102 years, respectively. Po-210, with a half-life of 138.4 days, is the most readily available isotope and is extremely toxic. Atomic number 84; melting point 254°C; boiling point 962°C; specific gravity 9.20; valence 2, 4, 6. cross-reference: Periodic Table.
from The Century Dictionary.
- noun A radioactive substance discovered in pitchblende by M. and Mme. Curie in 1898: named in honor of Poland, the native country Of Mme. Curie.
from the GNU version of the Collaborative International Dictionary of English.
- noun (Chem.) A radioactive chemical element, discovered by M. and MMe. Curie in pitchblende, and originally called
radium F. It has atomic number 84 and an atomic weight of 210. It is a very rare natural element, having an abundance in uranium ores only 0.2% that of radium. It is closely related chemically to bismuth. It emits only alpha rays, and has a half-life of 138 days. It is thus more unstable than radium, and a milligram of polonium emits as many alpha particles as 5 grams of radium. Twenty-seven isotopes are known, with atomic masses from 192 to 218. At present a more practical method of preparation than isolation from ores is the preparation by neutron bombardment of bismuth in a nuclear reactor, and it may be obtained commercially by users having an appropriate permit.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun a chemical element (symbol Po) with
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- noun a radioactive metallic element that is similar to tellurium and bismuth; occurs in uranium ores but can be produced by bombarding bismuth with neutrons in a nuclear reactor
from The American Heritage® Dictionary of the English Language, 4th Edition
from Wiktionary, Creative Commons Attribution/Share-Alike License
I have now managed to get Meyer to write a letter to Curie asking to send one of our scientists, Frau Doctor Rona, chemist and specialist in polonium, to her lab for three weeks in order to learn the art from Irene Curie ...
Elisabeth Rona, one of the female experimenters who worked at the institute and who specialized in polonium preparations, seemed to be one of the few who had a clear sense of how hazardous radiation could be.
In the absence of any other option, the woman who was one of the most distinguished experts in polonium preparations eventually spent October through December of 1938 in Sweden, working on oceanography. 170 Her close friend Gleditsch offered her another temporary solution.
We found that pitchblende contains at least two radioactive materials, one of which, accompanying bismuth, has been given the name polonium, while the other, paired with barium, has been called radium.
It is the triggers in these devices that need the maintenance, which is a re supply of a nuclear chemical called polonium 210.
Eight years later, one of them did die: Alexander Litvinenko, poisoned in London last November by a rare radioactive isotope called polonium 210.
Remember the case of the former Russian spy that was murdered in London with that highly radioactive substance called polonium 210?
NEWTON: What actually got him, investigators say, is a rare radioactive element called polonium-210.
MATTINGLY: But, as Russian authorities pledged cooperation, British health officials revealed, Litvinenko was killed by a highly lethal radioactive substance called polonium 210.
Twenty-two days later, Alexander Litvinenko died in a London hospital, his organs ravaged by a rare radioactive isotope called polonium 210.