GC: n
CT: Polonium is an extremely unstable radioactive chemical element which forms as part of the decay process of radium, another radioactive element. Because polonium is a stage in radium’s decay process, it is sometimes called radium F. This element appears in trace amounts in nature, typically in uranium ores, and most of its uses are in theoretical physics. It does have some industrial uses, but because of its radioactivity, consumers are unlikely to encounter it.
S: WG – http://www.wisegeek.com/what-is-polonium.htm (last access: 4 December 2015)
N: 1. Discovered by Marie Curie (born Skłodowska), 1867-1934, and her husband, and named for her native country, Poland (Modern Latin Polonia). With element-name ending -ium.
2. All polonium isotopes are radioactive, and all are shortlived except the three α-emitters, artificially produced 208 Po (2.9 years) and 209 Po (100 years), and natural 210 Po (138.4 days).
3. Group: 16
Melting point: 254°C, 489°F, 527 K
Period: 6
Boiling point: 962°C, 1764°F, 1235 K
Density: 9.20 grams per cubic centimeter
Atomic number: 84
Relative atomic mass: 209
State at 20°C: Solid
Key isotopes: 209Po, 210Po
Ionization energy: 8.417 eV
Atomic weight: 209
Polonium is an alpha-emitter, and is used as an alpha-particle source in the form of a thin film on a stainless steel disc. These are used in antistatic devices and for research purposes.
A single gram of polonium will reach a temperature of 500°C as a result of the alpha radiation emitted. This makes it useful as a source of heat for space equipment.
It can be mixed or alloyed with beryllium to provide a source of neutrons.
4. In laboratories, polonium is used as a source of neutrons for experiments. It can be produced by bombarding a bismuth isotope with alpha particles; polonium produced through this practice is also used in nuclear reactors. The element also appears in some devices which are designed to reduce or eliminate static, and it is sometimes used in the manufacture of spark plugs, as well. Polonium has 34 isotopes, all of which happen to be radioactive as well.
S: 1. OED – http://www.etymonline.com/index.php?allowed_in_frame=0&search=polonium&searchmode=none (last access: 4 December 2015). 2. AS – http://www.accessscience.com/content/polonium/533400 (last access: 4 December 2015). 3. RSC – http://www.rsc.org/periodic-table/element/84/polonium (last access: 4 December 2015). 4. WG – http://www.wisegeek.com/what-is-polonium.htm (last access: 4 December 2015).
SYN:
S:
CR: natural uranium, nuclear energy, uranium .
