A very rare element in nature, polonium is found in
uranium ores at about 100
micrograms per
metric ton (1:1010). Its natural abundance is approximately 0.2% of the abundance of radium.
In
1934 an experiment showed that when natural
209Bi is bombarded with
neutrons, 210Bi, which is the parent of polonium, was created. Polonium may now be made in milligram amounts in this procedure which uses high neutron fluxes found in
nuclear reactors. Only about 100 grams is believed to be produced each year, making polonium exceedingly rare.
Thallium (
IPA: /ˈθaliəm/) is a
chemical element in the
periodic table that has the symbol
Tl and
atomic number 81.
[1] This soft gray malleable
poor metal resembles
tin but discolors when exposed to air. Thallium is highly
toxic and is used in
rat poisons and
insecticides but since it might also cause
cancer (although the
EPA does not class it as carcinogen), this use has been cut back or eliminated in many countries. It is also used in
infrared detectors.
[2] It has even been used in some
murders, earning the nicknames "The Poisoner's Poison" and "Inheritance powder" (alongside
arsenic).