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List, data and properties of all known isotopes of Polonium. All atomic nuclei of the chemical element polonium are summarized under polonium isotopes; these all consist of an atomic nucleus with 84 protons and, in the uncharged state, 84 electrons. The difference between each polonium isotope is based on the number of neutrons in the nucleus.
1 Νοε 2023 · Polonium-210 (210 Po) is typically artificially produced in nuclear reactors by bombarding the stable isotope bismuth-209 (209 Bi) (via the (n, γ) reaction, yielding 210 Bi, which decays with a half-life of T = 5 days to 210 Po) (Health Physics Society, 2008). Determining the atomic mass of polonium was a very challenging task.
Its abundance in the Earth’s crust is about one part in 10 15. It occurs in nature as a radioactive decay product of uranium, thorium, and actinium. The half-lives of its isotopes range from a fraction of a second up to 103 years; the most common natural isotope of polonium, polonium-210, has a half-life of 138.4 days.
The longer-lived isotopes of polonium, 208 Po and 209 Po, can be formed by proton or deuteron bombardment of bismuth using a cyclotron. Other more neutron-deficient and more unstable isotopes can be formed by the irradiation of platinum with carbon nuclei.
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.
13 Οκτ 2023 · Polonium has 29 isotopes with known half-lives, with mass numbers ranging from 190 Po to 218 Po. None of them are secure. The most stable isotope, having a half-life of 102 years, is 209 Po. Polonium has an atomic number of 84 and is a silvery metal. It has a melting point of 254 °C (489 °F) and a boiling point of 962 °C ( 1764 °F).
Today, all isotopes between mass numbers 193 and 218 are known. The longest-lived isotope is 209 Po (t 1/2 = 102 years). Nearly all the chemical and physical studies on polonium were performed with the pure α emitter 210 Po (t 1/2 =138 day). Figure 1 shows the naturally occurring polonium isotopes.
