Mini-Research ELECTRON- In 1897, Sir J. J. Thomas, an English physicist, measured the deflection of cathode-ray particles in magnetic and electrical fields. As a result he found the ratio of the charge, e, to the mass, m, of the cathode-ray particles. He found e / m identical to those particles irrespective of the metal the electrodes were made of or the kind of gas in the tube. In 1909, RA Millikan, an American scientist, measured that charge.
All electrons are found to be identical no matter their source or the method of liberating them from matter. From the values of e / m , and e, the mass of an electron was calculated to be. 00055 amu. PROTON- Eugen Goldstein used a Crookes tube with holes in the cathode, and observed that another kind of ray was emitted from the anode and passed through the holes.
He discovered this in 1886. In 1889, William Wien showed these rays to be positively charged. The ratio of charge to mass was smaller than electrons, but varied in different gasses. This meant that either charge varied, mass varied or both varied. Both vary. Charge is equal to an electron, but opposite in sign.
Mass was smaller when used as a gas. From the values of e / m for positive particles, m was calculated to be 1. 0073 amu. This became known asa proton. NEUTRON- In 1932, James Chadwick detected the third of the basic parts of an atom. He showed that uncharged particles, or neutrons, are emitted when atoms of other elements are bombarded with high-velocity helium atoms with all electrons removed, or an alpha particle.
The Essay on Charged Lepton Electron Magnetic Charge
The Discovery Of The Electron The electron was discovered in 1895 by J. J. Thomson in the form of cathode rays, and was the first elementary particle to be identified. The electron is the lightest known particle which possesses an electric charge. Its rest mass is Me approximately equal 9. 1 x 10 -28 g, about 1/1836 of the mass of the proton or neutron. The charge of the electron is -e = -4. 8 x ...
Neutrons were determined to have amass of 1. 0087 amu. They are unstable outside of an atom and slowly degenerate to form protons and electrons.
