Astatine is the rarest naturally occurring element on the Earth. Nuclei of its most stable isotope At 85 210 only last an average of 12 hours before they decay by alpha decay. What does At 85 210 decay into?

The most stable isotope of Astatine, At 85 210 lasts only 12 hours before it decays by alpha decay. Alpha decay is a type of radioactive decay in which an atomic nucleus produces an alpha particle and so transforms or decays into a separate atomic nucleus with a reduced mass number of four and a reduced atomic number of two. At 85 210 → α 2 4 + Bi 81 206 and after alpha decay it forms Bismuth.

Radon gas Rn 86 222 is formed when Uranium- 234 Ur 92 234 decays by a series of alpha decays. How many alpha decays are required for this to happen?

Radon gas Rn 86 222 is formed when Uranium- 234 Ur 92 234 decays by a series of alpha decays. Alpha decay is a type of radioactive decay in which an atomic nucleus produces an alpha particle and so transforms or decays into a separate atomic nucleus with a reduced mass number of four and a reduced atomic number of two. So in this case, Uranium is changed to radon. The atomic number is changed by 6 which means a total of 3 alpha decays are necessary.