When did scientists start discovering and wondering about subatomic particles?

Answer 1

Probably with the discovery of the "Rutherford atom", the early model of atoms having a nucleus orbited by electrons, from the Rutherford scattering experiments in 1907. The earliest experiment showing the existence of particles other than atoms was the Thompson experiment in 1897 leading to the discovery of the electron as a particle. But earlier thinkers had already been speculating on such particles decades or even centuries before either experiment. For example, Issac Newton hypothesized that light was corpuscular in nature, or like particles, before later experimenters showed its wave behavior. Only when Planck with his blackbody calculations and Einstein with his photoelectric experiments came along was light was once again viewed as photon particles, or photons with both wave and particle properties.

Answer 2

J. J. Thomson discovered electrons in 1897. In 1905 Albert Einstein demonstrated the physical reality of the photons which were postulated by Max Planck in order to solve the problem of black body radiation in thermodynamics.

Answer 3

Around the 1950's after Watson and Crick successfuly created a model of deoxyribosenuclei acid.

Answer 4

Most likely when they started to question whether or not atoms were the smallest possible thing in the universe.

Answer 5

Read about Madame Curie.

Answer 6

A looong time agooooo!