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460
Democritus
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John Dalton
John Dalton was an English chemist . His ideas formed the atomic theory of matter. His some of the ideas were : All matter is made of atoms.2) Atoms are indivisible and indestructible. 3) Compounds are formed by a combination of two or more different kinds of atoms. -
J.J Thompson
J.J was an English chemist .He discovered the electron when he was experimenting with gas discharge tubes. He noticed a movement in a tube. He called the movement cathode rays. The rays moved from the negative end of the tube to the positive end.He realized that the rats were made of negatively(electrons) charged particles.In 1904 Thomson suggested a model of the atom as a sphere of positive matter in which electrons are positioned by electrostatic forces. -
Lord Ernest Rutherford
Ernest Rutherford conducted a famous experiment called the gold foil experiment .He used a thin sheet of gold foil .He also used special equipment to shoot alpha particles at the gold foil .The experiment shows :
- Atoms are made of a small positive nucleus;positive nucleus repels positive alpha particles
-Atoms are mostly empty space . -
Niels Bohr
Niels Bohr was a Danish physicist who made foundational contributions to understanding atomic structure and quantum theory ,depicts the atom as a small, positively charged nucleus surrounded by electrons that travel in circular orbits around the nucleus—similar in structure to the solar system, but with attraction provided by electrostatic forces.https://www.youtube.com/watch?v=GhAn8xZQ-d8v
