I have just finished reading "The Making of the Atomic Bomb" by Richard Rhodes.
It is a superb book, putting physics in context. It contains a lot of
physics/chemistry with the puzzles of the time well illustrated. e.g. Fermi
doing a neutron activation experiment and getting different results when he did
it on different tables in his lab, one wooden, one marble. It is 800 pages,
but quite cheap in paper.