James Chadwick: The Physicist Who Solved the Atomic Nucleus Puzzle

On October twentieth, eighteen ninety-one, James Chadwick was born in Bollington, England. He was a physicist, and his academic field was atomic and nuclear physics.

Chadwick's groundbreaking work solved one of the greatest puzzles in early twentieth-century atomic physics: what held the atomic nucleus together. Physicists knew the nucleus contained positively charged protons, but they did not understand how it could be stable without a corresponding negative charge inside it. In nineteen thirty-two, after systematic research building on the work of others, Chadwick managed to prove the existence of a new, neutral particle in the nucleus – the neutron. This discovery not only explained the stability of the atom but also the concept of isotopes. The neutral neutron also proved to be the key to splitting the atomic nucleus, as it was not repelled by the positive charge. For this fundamental discovery, which opened the door to the entire field of nuclear physics and the development of atomic energy, James Chadwick was awarded the Nobel Prize in Physics in nineteen thirty-five.