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bismuth-209
Sign in to saveAlso known as Bi-209, 209Bi
Bismuth-209 (Bi) is an isotope of bismuth with the longest known half-life of any nuclide that undergoes α-decay (alpha decay); the decay product is thallium-205. It has 83 protons and a magic number of 126 neutrons, and naturally-occurring bismuth consists entirely of this isotope.
Key facts
- Isotope.parent2_decay
- b+
- Isotope.parent3
- astatine-213
- Isotope.mass_number
- 209
- Isotope.symbol
- Bi
- Isotope.num_neutrons
- 126
- Isotope.num_protons
- 83
- Isotope.abundance
- 100%
- Isotope.mass
- 208.980399
- Isotope.spin
- 9/2−
- Isotope.decay_mode1
- Alpha emission
- Isotope.decay_energy1
- 3.1373
- Isotope.decay_product
- thallium-205
- Isotope.decay_symbol
- Tl
- Isotope.decay_mass
- 205
- Isotope.parent
- lead-209
- Isotope.parent_symbol
- Pb
- Isotope.parent_mass
- 209
- Isotope.parent_decay
- b
via Wikipedia infobox
~4 min read
Encyclopedic overview
9 sectionsContents
- Decay properties
- Applications
- Synthesis of other elements
- Formation
- Primordial
- Radiogenic
- See also
- Notes
- References
Bismuth-209 (Bi) is an isotope of bismuth with the longest known half-life of any nuclide that undergoes α-decay (alpha decay); the decay product is thallium-205. It has 83 protons and a magic number of 126 neutrons, and naturally-occurring bismuth consists entirely of this isotope.
== Decay properties == Bismuth-209 was long thought to have the heaviest stable nucleus of any element, but in 2003, a research team at the in Orsay, France, discovered that Bi undergoes alpha decay with a half-life now given more precisely as years (20.1 quintillion years), over 10 times longer than the estimated age of the universe. The heaviest nucleus considered to be stable is now lead-208 and the heaviest stable monoisotopic element is gold (gold-197).
Excerpted from Wikipedia’s “bismuth-209” article, available under the CC BY-SA 4.0 licence.