Final answer:
J.J. Thomson is usually given credit for the discovery of the electron through his cathode ray experiments. He proposed the 'plum pudding' model to represent the atomic structure.
Step-by-step explanation:
J.J. Thomson is usually given credit for the discovery of the electron. In 1897, Thomson discovered and identified the electron as the smallest quantity of electric charge in his cathode ray experiments. He proposed the first model of atomic structure known as the 'plum pudding' model, where electrons were embedded in a positively charged matter.