Q. What is the half life of the longest lived isotope of Francium?
Answer: 21 minute
Notes: Francium is highly radioactive. its longest-lived isotope ²²³Fr has a half-life of only 21 minutes.

This question is part of 40000+ General Studies MCQ Series Course on GKToday Android app. Question Number: 33 in Chemistry-3-Elements in above course in App.