Actinide Series

Name:
Actinide Series
Detailed information:
(actinoid series). The group of radioactive elements starting with actinium and ending with element 105. All are classed as metals. Those with atomic number higher than 92 are called transuranic elements. The series includes the following elements: actinium, 89; thorium, 90; protoactinium, 91; uranium, 92; neptunium, 93; plutonium, 94; americium, 95; curium, 96; berkelium, 97; californium, 98; einsteinium, 99; fermium, 100; mendelevium, 101; nobelium, 102; and lawrencium 103. The isotopes of several of these elements are under study for possible use in such fields as radiography, neutron activation analysis, hydrology, and geophysics.