Which scientist demonstrated the existence of neutrons in the nucleus?

Which scientist demonstrated the existence of neutrons in the nucleus?

• A. John Dalton
• B. James Chadwick
• C. Ernest Rutherford
• D. J. J. Thomson

Answer: (B)

Neutrons are neutral particles inside the nucleus that add mass without changing the atom’s charge. James Chadwick showed they exist by studying the radiation produced when alpha particles hit beryllium. This radiation could knock protons out of other materials, and it wasn’t affected by magnetic fields, indicating it was made of neutral particles with substantial mass. By analyzing the energy and behavior of these particles, he concluded they were neutrons, residing in the nucleus alongside protons. This discovery completed the basic picture of the nuclear composition that earlier scientists had begun to uncover.

Neutrons are neutral particles inside the nucleus that add mass without changing the atom’s charge. James Chadwick showed they exist by studying the radiation produced when alpha particles hit beryllium. This radiation could knock protons out of other materials, and it wasn’t affected by magnetic fields, indicating it was made of neutral particles with substantial mass. By analyzing the energy and behavior of these particles, he concluded they were neutrons, residing in the nucleus alongside protons. This discovery completed the basic picture of the nuclear composition that earlier scientists had begun to uncover.