3 ms·https://youtu.be/rv-mFSoZOkE https://youtu.be/rv-mFSoZOkE Longer half-lives = less radioactivity.by petre 8y agohttps://youtu.be/rv-mFSoZOkE https://youtu.be/rv-mFSoZOkE Longer half-lives = less radioactivity.