GENERAL KNOWLEDGE

Detailed explanation-1: -Polonium has 42 known isotopes, all of which are radioactive. They have atomic masses that range from 186 to 227 u. Po (half-life 138.376 days) is the most widely available and is made via neutron capture by natural bismuth.

Detailed explanation-2: -Twenty five isotopes of polonium are known, with atomic masses ranging from 194 to 218. Polonium-210 is the most readily available.

Detailed explanation-3: -Scientists at the National Institute of Standards and Technology (NIST) have determined* that polonium-209, the longest-lived isotope of this radioactive heavy element, has a half-life about 25 percent longer than the previously determined value, which had been in use for decades.