Where did early studies of atomic energy take place?

The first atomic device tested successfully at Alamagordo in New Mexico on 16 July 1945. It used plutonium made in a nuclear pile.

Explanation:

the difference is that white collar worker performs skills like worker as a scientist or well blue collars do physical work and they do services like being a cook.

the second significant cause of the great migration was the desire of black southerners to escape segregation, known euphemistically as jim crow. rural african american southerners believed that segregation - and racism and prejudice against blacks - was significantly less intense in the north.