Passage: Kamen was born August 27, 1913, in Toronto, the son of Russian Jewish immigrants. He grew up in Chicago. He received a bachelor's degree in chemistry from the University of Chicago in 1933 and obtained a PhD in physical chemistry from the same university in 1936. Thereafter he sought a research position in chemistry and nuclear physics under Ernest Lawrence at the radiation laboratory in Berkeley, where he worked without pay for six months until being hired to oversee the preparation and distribution of the cyclotron's products. Although carbon-14 was previously known, the discovery of the synthesis of carbon-14 occurred at Berkeley when Kamen and Ruben bombarded graphite in the cyclotron in hopes of producing a radioactive isotope of carbon that could be used as a tracer in investigating chemical reactions in photosynthesis. Their experiment resulted in production of carbon-14.

Question: When did Kamen get his PhD?
1936