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John Dalton
The English chemist, John Dalton did many experiments and his ideas made the atomic theory of matter. It states that all elements are composed of atoms and it is impossible to divide or destroy an atom. All atoms of the same element are alike. Atoms of different elements are different. He also believed that atoms of different elements combine to form a compound. It looks like a small indivisible sphere that is colored. Later on he added rings,electrons, protons, and neutrons. -
J.J. Thompson
J.J. Thompson was an English scientist who was experimenting with gas discharge tubes. He noticed a movement in the tube and called the movement cathode rays. The rays moved from the negative end to the positive end. He realized the rays were made of negatively charged particles which were electrons. His model consists of electrons and a spherical cloud of positive charge. -
Lord Ernest Rutherford
Rutherford did a famous experiment called the Gold Foil Experiment. In that experiment he used a thin sheet of gold foil. he also used special equipment to shoot alpha particles which are positively charged at the gold foil. He saw most particles going through the foil, but some were deflected. The experiment shows atoms are made of a small positive charged nucleus and they are mostly empty space. His model contains the protons, neutrons, and electrons similar to the modern model today. -
Niels Bohr
The Danish physicist Niels Bohr created a model similar to the solar system. The electrons go around the nucleus like all the planets orbit around the sun. All electrons have their energy levels which is a certain distance from the nucleus. Each energy level can hold a certain number of electrons. Level 1
