Name the physicist who first gave the exchange theory of nuclear forces.

The exchange theory of nuclear forces was first proposed by Japanese physicist Hideki Yukawa in 1935. Yukawa suggested that the strong nuclear force, which binds protons and neutrons together in the atomic nucleus, arises from the exchange of particles between these nucleons. He theorized the existence of a new particle, later called the pion (or pi-meson), which mediates this force.

Yukawa’s theory successfully explained the short-range nature of the strong nuclear force, as the mass of the pion predicted a limited range for the interaction. His groundbreaking work provided critical insights into the structure of the atomic nucleus and marked the beginning of modern particle physics. For his contributions, Yukawa was awarded the Nobel Prize in Physics in 1949.