Chaim Weizmann, (1874-1952). Jewish statesman and chemist, born in Russia. Through his research work for the British War Office during World War I he discovered a process to produce acetone, used in explosives. An active Zionist, he negotiated with the British to establish a Jewish homeland in Palestine and was head of the World Zionist Organization (1920-30; 1935-46). He later became the first president of the state of Israel (1949-52).