Ví dụ công khai
Mendelevium, the heaviest and rarest form of matter known, has been produced in the University of California's cyclotron. Identity based on only 17 atoms of new element [subtitle]. […] Mendelevium is intensely radioactive, decaying by spontaneous fission. Its half-life is between a half hour and three hours. It has chemical properties similar to those of thulium, element 69, a rare earth.