Which nuclear physicist fled Germany to England in 1933, contributed to the Manhattan Project in the U.S., and passed secrets to the USSR?

• A. Enrico Fermi
• B. Klaus Fuchs
• C. Albert Einstein
• D. Werner Heisenberg

Answer: (B)

This question tests your ability to connect a scientist’s life story with a famous act of espionage during the WWII era. Klaus Fuchs fits this profile: he fled Germany in 1933 to escape Nazi persecution and settled in Britain, where he joined the early atomic research efforts. He later worked on the Manhattan Project in the United States, contributing to its theoretical development. At the same time, he passed detailed information about the bomb’s design to the Soviet Union, making him a key figure in Cold War spying.

The other figures don’t match all parts of the clue. Enrico Fermi was an Italian physicist who contributed to the Manhattan Project but did not flee Germany in 1933 nor appear as a Soviet spy. Albert Einstein, while he left Germany in 1933 and supported early wartime research, did not work on the Manhattan Project or pass bomb-design secrets to the USSR. Werner Heisenberg remained in Germany and did not flee to England or the U.S. to contribute to the Manhattan Project or espionage.