In 1919 Rutherford had discovered the proton, a positively charged particle within the atom's nucleus.

Who discovered the proton?

It is 100 years since Ernest Rutherford published his results proving the existence of the proton.

Which discovered first electron or proton?

The first subatomic particle to be identified was the electron, in 1898. Ten years later, Ernest Rutherford discovered that atoms have a very dense nucleus, which contains protons. In 1932, James Chadwick discovered the neutron, another particle located within the nucleus.