In 1954, after he had develop the atomic bomb, j. robert oppenheimer was investigated and denied future access to classified information because

He had communist friends and family.

Explanation:

Hello,

In this case, it is widely known that Robert Oppenheimer (1904-1967) was a scientist who was part of the Manhattan Project formed to create the atomic bomb. At the Los Alamos laboratory he performed his scientific work in the light of researching and designing the bomb, that is why he is the soc-called father of such bomb. By 1954, the lifeguards he had were removed, he started being investigated as well as his future access to the classified information was revoked since it was dug up he had friends and family supporting and living based on the communism.  

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that's what i got you can count the number of atoms