In 1919, Rutherford did an experiment of bombarding nitrogen nuclei with alpha particles. As shown in the figure, radioactive substance A was placed in container C, and the alpha particles emitted from A were shot on aluminum foil F. After the thickness of aluminum foil was properly selected, the alpha particles were just absorbed by F and could not penetrate. A fluorescent screen S was placed behind F, and a microscope was used to observe whether there was a flash on the fluorescent screen. After nitrogen was introduced into C through valve T, Rutherford observed the flash from the fluorescent screen S, and changed the nitrogen into oxygen or carbon dioxide, but no flash was observed, which indicated that the flash must be caused by the new particles produced after α particles hit the nitrogen nucleus penetrating through the aluminum foil.

Rutherford introduced this kind of particle into electric and magnetic fields, measured its mass and electric quantity according to its deflection in electric and magnetic fields, and determined that it was a hydrogen nucleus, also known as proton. Rutherford usually used the symbol to introduce this kind of particle into electric and magnetic fields, and measured its mass and electric quantity according to its deflection in electric and magnetic fields, and determined that it was a hydrogen nucleus, also known as proton, usually represented by symbols.

Extended information

1. Finder

Ernest Rutherford (English: 1st Baron Rutherford of Nelson, August 3, 1871-October 19, 1937)

A famous British physicist, well-known as the father of nuclear physics. Academic circles recognized him as the greatest experimental physicist after Faraday.

second, antiproton

antiproton (English: antiproton) is a composite particle. The antiproton of proton has the same mass and spin as that of proton, and has the same lifetime as that of proton, but its charge and magnetic moment are opposite to that of proton, with the same negative charge as that of electron. When it meets a proton, it will be annihilated and converted into energy.

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