Polonium is the chemical element with symbol Po and atomic number 84 in the periodic table. It is chemically similar to selenium and tellurium, though its metallic character resembles that of its horizontal neighbors in the periodic table: thallium, lead, and bismuth. Its natural occurrence is limited to tiny traces of the fleeting polonium-210 in uranium ores, as it is the penultimate daughter of natural uranium-238. Though slightly longer-lived isotopes exist, they are much more difficult to produce.
It was discovered in 1898 by Marieand Pierre Curie, when it was extracted from the uranium ore pitchblende and identified solely by its strong radioactivity: it was the first element to be so discovered. Polonium was named after Marie Curie’s homeland of Poland. Polonium has few applications, and those are related to its radioactivity: heaters in space probes, antistatic devices, sources of neutrons and alpha particles, and poison. It is a radioactive element and extremely dangerous to humans.
Characteristics of Polonium
- Polonium is a rare, silvery-gray, radioactive, low-melting metalloid. Polonium readily reacts with dilute acids, but only slightly with alkalis. All of its isotopes are radioactive.
- The energy released by polonium’s alpha decay is considerable and heats the space around it. The energy released is so large (140 W/g) that a capsule containing about half a gram reaches a temperature above 500 °C.
- It’s a silvery-grey, radioactive semi-metal found in uranium ores. It is chemically similar to elements – bismuth and tellurium.
Uses of Po
- It is used to eliminate static electricity produced during processes such as rolling paper, wire and sheet metal.
- Due to alpha emission, 1 gram of polonium can acquire a temperature of 500°C. This property of Polonium makes it a useful source of heat for space equipment.
- It is used as a source of neutrons by mixing it or alloying it with beryllium.
- Po210 is used as an atomic heat source. The only disadvantage is the isotope’s short half-life i.e. 138.4 days. Therefore, it doesn’t provide power for long-term uses.