41. Before this time the actinides were thought to be forming a fourth d-block row. 42. All proposed nuclear reactors except specially designed and operated actinide burners experience some degree of conversion. 43. Several countries are developing reprocessing methods that do not separate the plutonium from the other actinides . 44. Selective Actinide Extraction ( SANEX ). 45. Examples are the lanthanides and actinides . 46. Uranium is a member of the Actinide chemical series on the periodic table of the elements. 47. The curves for the fission of the later actinides tend to make even more shallow valleys. 48. Chemical elements contains 11 transuranic actinide elements, with atomic numbers ranging from 93 to 103. 49. Californium is the heaviest actinide to exhibit covalent properties, as is observed in the californium borate. 50. In 1945, actinide elements, like the lanthanides, were filling an f sub-level.
