1 jun 1904 ano - Sir Joseph John Thomson creates the "pudding model"

Descrição:

Thomson, much earlier in 1897 discovered that 'cathode rays' (a beam emitted from a very low -pressure tube, a vacuum). Upon closer inspection and many calculations, he found the electron, the first sub-atomic particle was found- Thomson also noted that it had a very high negative charge for its size. He realised that there must also be a counter-acting positive charge. Thus, he made the "pudding model".