Bohr’s model introduced the concept of quantized energy levels and laid the groundwork for modern quantum mechanics, revolutionizing our understanding of atomic behavior.

E. Goldstein discovered positively charged radiations called canal rays in a gas discharge, which ultimately led to the discovery of another sub-atomic particle, the proton.

Observations of how different materials interacted with static electricity suggested that atoms were not indivisible, as some substances conducted electricity while others did not.

Dalton’s work laid the foundation for understanding atomic structure by introducing the concept of atoms as the fundamental units of elements.