Today we will take a closer look at an element that you most probably did not know was radioactive, Bismuth.

Bismuth was first discovered in 1753 and is probably most famous for its very characteristic crystal structure and absolutely stunning colours. In nature, it has only one isotope, ²⁰⁹Bi, which is also one of the primordial elements.

Primordial elements are elements that have existed in their current form before the Earth was formed. As of right now, there are 252 stable and 34 radioactive primordial isotopes.

From the moment of its discovery, scientists believed that Bismuth was a stable element but in 2003, it was found out that Bismuth 209 undergoes alpha decay into Thallium 205 with a half-life of 2.01×10¹⁹ years which is over 1 billion times the age of the universe! The reason why Bismuth’s radioactivity was discovered so late is because of its very low activity, 3 Bq/1000kg, making it extremely hard to detect. Due to an extremely long half-life and very low activity, Bismuth is often treated as a non-radioactive element.

Today, Bismuth is mainly used in the production of cosmetics and medicine so theoretically, every time you apply makeup, you put radioactive material on your face!