June 15, 2020
For educational institutions
⟶ Updated 15 Oct 2017 ⟶
List of edits
-Democritus was a Greek philosopher who lived from 470-380 B.C, and is considered the father of atomic thought. Democritus claimed that all matter was made of small, indestructible particles called ‘atomos’. This hypothesis was created in 465 B.C
-John Dalton was a British chemist who was credited for pioneering modern atomic theory in 1803 from experimenting with gases, which led John Dalton to create the first atomic model which consisted of only a single ball, with no protons, neutrons or electrons as they had not yet been discovered.
-Frederick Soddy was an English chemist who in 1912, hypothesised that elements could exist in different forms, proposing the idea of isotopes.
-Max Planck was a German Theoretical Physicist and considered the father of quantum theory, as he created it in 1900. By discovering that energy did not flow evenly but rather in packets (which he called "quanta.") Planck created an equation to predict this phenomenon, which includes a constant now known as "Planck's constant." Planck's discovery ended what many people now call "classical physics" and began the study of quantum physics.
-J.J Thomson was responsible for the discovery of the electron in 1897 using a cathode ray tube, and proposed the ‘Plum Pudding’ atomic model in 1904. The Plum Pudding atomic model consisted of electrons within a positive atom.
-Niels Bohr was a theoretical nuclear physicist. Bohr proposed a theory in 1913 that electrons existed in set orbits around the nucleus, and was the key to the periodic repetition of properties of the elements. Bohr improved rutherford's model, making it so that electrons orbited around the nucleus in a fixed manner
-James Chadwick was an English Physicist who was responsible for discovering the neutron in 1932 by using scattering data to calculate the mass of the neutral particle.
-Ernest Rutherford was responsible for creating the Rutherford atomic structure in 1911 by making the discovery that nearly the total mass of the atom was located in the nucleus. Rutherford discovered this using his well known gold-foil experiment, demonstrating that the atom has a heavy nucleus. Rutherford's atomic structure consisted of a positively charged nucleus orbited by electrons
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