In 1949, de-Shalit earned his master's degree in physics at the Hebrew University of Jerusalem under the guidance of Giulio Racah.

De-Shalit and his fellow students wrote a letter to Israeli Prime Minister David Ben-Gurion to point out the vital importance of nuclear physics for Israel's future.

Their sons, Ehud and Avner are professors of mathematics and political science, respectively, at the Hebrew University of Jerusalem.

In 1954, de-Shalit was asked to establish the Department of Nuclear Physics at the Weizmann Institute of Science, which he headed for ten years.

In 1957/58 de-Shalit spent a sabbatical year at CERN as a Ford Foundation Fellow.