60-inch cyclotron. Enough material has been made for chemical studies by tracer technique in the way in which the properties of element 93 (neptunium ; Np) and 94 (plutonium ; Pu) were first ...

Americium is gradually decaying to become another element 'called neptunium. 'Neptuniam atoms are much more stable. JON CHASE:'As more and more of the atoms become neptunium, 'the material becomes ...