• WordNet 3.6
    • n polonium 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
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Webster's Revised Unabridged Dictionary
    • n Polonium (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.
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Century Dictionary and Cyclopedia
    • n polonium A radioactive substance discovered in pitchblende by M. and Mme. Curie in 1898: named in honor of Poland, the native country Of Mme. Curie. It was found that bismuth precipitated by sulphureted hydrogen from an acid solution of pitchblende carried down with it something possessed of marked radioactivity. The radiation caused electrical conduction in gases, rendered phosphorescent a screen coated with barium platinocyanide, and produced a latent image on a photographic plate protected by a screen opaque to ordinary light The radioactive substance in question was found to resemble bismuth, not only in being thrown down by sulphureted hydrogen, but in furnishing salts soluble in acid but precipitated by water and by ammonia. Partial separation from bismuth was effected, but only to the extent of producing salts of the latter metal of considerably increased radioactivity. Polonium is identical with the radioactive bismuth of Giesel and the radiotellurium of Marckwald. The last-named investigator has gene much farther in the separation of polonium from other substances. By deposition from solution on a plate of metallic bismuth, and by precipitation by stannous chlorid, separating bismuth and in part tellurium, an extremely active product was obtained, but in very small quantity—only 1.5 gram from 2 tons of pitchblende. Afterward, by precipitating all remaining tellurium by hydrazine hydrochlorid, and throwing down the polonium by stannous chlorid, the radioactive substance was obtained in the finally concentrated state as a precipitate weighing only 4 milligrams, or 1 part from 500 million parts of pitchblende. The radioactivity of this final product was, however, extraordinary, one hundredth of a milligram sufficing to render a surface of zinc sulphid phosphorescent so that it could be seen by a large audience. Even in this most concentrated form no directly visible light is given off. The radiation is of the α or non-penetrating type. No gaseous emanation is given off, and activity is not induced on surrounding bodies. The activity of polonium gradually decreases, and falls to half its original value in 143 days. Rutherford has shown that polonium is a disintegration-product of radium and accordingly of uranium. It is the seventh successive product which has been identified as formed from the radium emanation, and is therefore known as radium G.—Polonium rays. See ray.
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Webster's Revised Unabridged Dictionary
NL. So named after Poland, in L. form Polonia, one of the discoverers being a Pole


In literature:

RADIUM (Polonium) F { a } 140 days.
"The Birth-Time of the World and Other Scientific Essays" by J. (John) Joly
Four successive alpha captures would give Polonium 203, not mercury.
"The Bramble Bush" by Gordon Randall Garrett
Curie, in her enthusiasm, named in honor of the land of her birth, polonium.
"Woman in Science" by John Augustine Zahm
Polonium, named by Mme.
"An Introduction to the History of Science" by Walter Libby

In news:

She discovered two new elements including radium and polonium and the theory of radioactivity.
A stain contained higher levels of polonium-210 than a typical sample, a scientist says.
Why Is Polonium Used in Assassinations.
Low concentrations of polonium are all around the environment.
Radiation poisoning from polonium -210 looks like the end stage of cancer.
I first wrote about Yassar Arafat and polonium -210 this summer when traces of the radioactive element were found in the personal effects of the dead former Palestinian leader.
Yasser Arafat poisoning questions surface again after polonium found in belongings.
Whether a radioactive substance called polonium -210 was involved in Yasser Arafat's death is under investigation.
Was Yasser Arafat assassinated with Polonium , or did he die from "Palestinium" as Israel claims.
Arafat's Widow Wants His Body Tested for Polonium .
Radiation tests showed unusually high levels of polonium -210 were present on the Palestinian leader's clothes when he died in 2004.
Polonium -210 Linked To Ex-Spy's Contact.
Murder by Polonium -210: A Widow's Stalled Quest for Justice.
Polonium 210 is a radioactive substance that is highly lethal if ingested.
In his final days, the leader didn't display any of the symptoms typically associated with polonium poisoning.

In science:

Behaviour of activities of U daughters in the crystals of sets 1, 2 and 3 is presented in Fig. 6 where the effect of anti-correlation between Po and U is clearly seen. One can suppose that the decrease of 210Po activity in the crystals of set 3 in comparison with set 1 is also due to evaporation of Polonium from melt.
Proceedings of the 1st International Workshop "Radiopure Scintillators for EURECA" (RPScint'2008)
The 214Bi and 214Pb reaction chain 209Bi+n → 210Bi (β gamma lines must be present in case of uranium or radium origin of the polonium.
Proceedings of the 1st International Workshop "Radiopure Scintillators for EURECA" (RPScint'2008)
This research pro ject has been partially supported by Polonium pro ject 7946/2010. D.
On multidimensional Mandelbrot's cascades
Discovery of thallium, lead, bismuth, and polonium.
Discovery of the thallium, lead, bismuth, and polonium isotopes
D (radiolead) and radium F (polonium and radio tellurium).
Discovery of the thallium, lead, bismuth, and polonium isotopes