It wasn't until 1919 that Rutherford finally identified the particles of the nucleus as discrete positive charges of matter. Using alpha particles as bullets, Rutherford knocked hydrogen nuclei out of atoms of six elements: boron, fluorine, sodium, aluminum, phosphorus, an nitrogen. He named them protons, from the Greek for ‘first‘, for they were the first identified building blocks of the nuclei of all elements. He found the protons mass to be 1,836 times as great as the mass of the electron.
