Two Americans and a Swede won the Nobel Physics Prize for research into the use of lasers to enrich uranium for atomic bombs. Another American and a Japanese won the prize for chemistry.
The two awards, worth $180,000 each, brought to six the number of American winners in the 1981 Nobel series that ended Monday.
The physics prize went to Nicolaas Bloembergen of Harvard University; Arthur Schawlow of Stanford University; and Kai Siegbahn, a Swede.
Roald Hoffmann of Cornell University and Kenichi Fukui, a Japanese, shared the 1981 Chemistry Prize for research on chemical reactions that help in the development of better drugs.