🏆 which
Which element has the longest half-life among radioactive elements commonly discussed?
ChemistryIsotopes
Quick Answer
Bismuth-209 has an extraordinarily long half-life of about 2 × 10^19 years, far longer than the age of the universe. It was once considered stable, but it is now known to be very weakly radioactive.
The Full Story
Bismuth-209 is famous for its incredibly long half-life, estimated at around 2 × 10^19 years. That is so long that it effectively behaves as stable for most practical purposes. It was long considered the heaviest stable isotope, until sensitive measurements confirmed its extremely rare alpha decay. Bismuth is used in alloys, cosmetics, and medicinal compounds, especially where low toxicity is important.
Key Facts
1.Bismuth-209 half-life: about 2 × 10^19 years
2.Once thought stable
3.Atomic number: 83
YouTube Angle
Suggested video title for this topic:
"The almost-stable isotope that barely decays"