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Democtritus
Democritus discovered that everything is made of atoms, and he claimed that if you cut something in half again and again that it would eventually be uncuttable. He gave us the word atomos, meaning uncuttable. -
John Dalton
His atomic theory said that elements consisted of tiny particles called atoms. All the atoms that make up the element have the same mass. All elements are different from each other due to differing masses. -
JJ Thomson
Thomson was a British scientist who discovered the electron, leading to his "Plum-puddling" model. He pictures electrons embedded in a sphere of positive electric charge. -
Albert Einstein
Einstein discovered E=mc2, which showed that the increased relativistic mass (m) of a body comes from the energy of motion of the body , its kinetic energy (E)—divided by the speed of light squared (c2). This equation expresses the fact that mass and energy are the same physical entity and can be changed into each other. -
Ernest Rutherford
The New Zealander proved JJ Thomson wrong by stating that an atom has a dense, positively charged nucleus. Electrons move randomly in the space around the nucleus. -
Niels Bohr
Bohr claimed that atoms are small, positively charged nucleuses surrounded by electrons that orbit around the nucleus. -
Wolfgang Pauli
†he Pauli exclusion principle states that no two electrons in an atom can occupy the same quantom state simultaneously. -
Aristotle
Aristotle did not believe in the atomic theory. He thought that all materials on Earth were not made of atoms, but of the four elements, Earth, Fire, Water, and Air. Most people followed Aristotle’s idea, causing Democritus’ idea- which was that all substances on Earth where made of small particles called atoms- to be over looked for about 2,000 years. Aristotle's view was finally proven incorrect and his idea is no longer taught.
