fermium-257 References fermium-257 chemical isotope Ask Anything Homework Help Written by The Information Architects of Encyclopaedia Britannica The Information Architects maintain a master list of the topics included in the corpus of Encyclopædia Britannica, and create and manage the relationships between them. The Information Architects of Encyclopaedia Britannica Britannica AI Ask Anything Learn about this topic in these articles: fermium6-hour half-life), and fermium-257 (100.5-day half-life) have been produced in a high-neutron-flux reactor by the intense slow-neutron irradiation of elements of lower atomic number, such as plutonium. Read More6-hour half-life), and fermium-257 (100.5-day half-life) have been produced in a high-neutron-flux reactor by the intense slow-neutron irradiation of elements of lower atomic number, such as plutonium. Read More