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Democritus believed that all atoms are small hard particles, are made of a single material formed into different shapes and sizes, and are always moving, and they form different materials by joining together.
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All matter is made of indivisible, indestructible atoms, all atoms of the same element are identical in mass and properties, compounds are formed by a combination of different atoms, and a chemical reaction is a rearrangement of atoms.
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Creator of the periodic table, and the periodic law. Which states that when elements are arranged according to their atomic number, elements with similar properties will appear at regular intervals.
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He assisted greatly to the study of cathode rays. He discovered protons in the experiment. They would knock the electrons of atoms and attract them to a positively charged electrode
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Thompson discovered the electron in 1897 and was the one that took the plum pudding model of the atom into consideration.
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He discovered hot objects don't emit energy continuously, like in a wave, instead, energy is emitted in small, specific amounts called quanta which became the origin of the quantum theory.
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Gold-foil experiment where he demonstrated that an atom has a tiny but heavy nucleus.
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The hydrogen atom based on quantum theory that energy is transferred only in certain well defined quantities. Electrons should move around the nucleus but only in prescribed orbits.
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He won the Nobel Prize in 1923 for the measurement of the electronic charge
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He's associated with the quantum mechanics which he published in 1925 at the age of 23.
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The atomic model is known as the quantum mechanical model of the atom
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Chadwick bombarded beryllium atoms with alpha particles that created an unknown radiation. This particle became neutron.
