For four years, James Chadwick was a prisoner ... Now head of Cambridge University's nuclear physics lab, Rutherford oversaw Chadwick's PhD in 1921 and then made him assistant director of the ...

In 1913, Niels Bohr revised Rutherford's model by suggesting that the electrons ... It wasn't until 1932 that James Chadwick was able to prove its existence. Chadwick used a version of ...