What Did Hantaro Nagaoka Discover About the Atomic Theory?


Jane Flores

Hantaro Nagaoka was a renowned Japanese physicist who made significant contributions to the field of atomic theory. He was born in 1865 in Tokyo and later went on to study physics at the University of Tokyo. After completing his studies, Nagaoka started working at the university as a professor and continued his research work.

Nagaoka’s most notable discovery was his model of the atom, which is also known as the Saturnian model. This model was proposed in 1904 as an improvement to J.J. Thomson’s atomic model, which had some limitations.

According to Nagaoka’s Saturnian model, the atom is composed of a positively charged central nucleus that is surrounded by concentric rings of negatively charged electrons. The electrons move around the nucleus in circular orbits without radiating energy. This model was different from Thomson’s atomic model, which suggested that electrons were scattered throughout the atom.

Nagaoka’s Saturnian model had several advantages over Thomson’s atomic model. One significant advantage was that it explained why some elements emit light when heated or put under a high voltage.

According to Nagaoka, when energy is applied to an atom in this way, one or more electrons jump from their orbit to another orbit that is farther away from the nucleus. As these electrons fall back to their original orbit, they release energy in the form of light.

Another advantage of Nagaoka’s model was that it could explain why some elements have multiple isotopes with different atomic masses. According to his theory, each electron ring can hold only a certain number of electrons, and when an atom has extra neutrons or protons, they are added to a new ring around the nucleus.

Despite its advantages, Nagaoka’s Saturnian model had some limitations as well. For instance, it couldn’t explain why certain elements have similar chemical properties but different masses.

In conclusion, Hantaro Nagaoka played a crucial role in advancing our understanding of atomic theory with his Saturnian model of the atom. Although his model had some limitations, it paved the way for further research and helped us gain a deeper understanding of the structure of atoms.