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400
Democritus
An ancient Greek philosopher by the name of Democritus, claims that all matter is made up of tiny, invisible particles. -
Period: 400 to
History of Atomic Theory
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Robort Boyle
He studdied science at Oxford University and continued to do experiments till the late 1650's. He experimented with air, and rejected Aristoles idea that matter is made up of 4 elements (water, air, fire and death). He thought that matter was made up of particles. -
Isac Newton
He postulated anwsers concerning the ultimate structure of matter by advancing the idea of atoms. He presented the idea of atoms having some level of internal structure. He anticipated the modern concept of molecules. -
John Dalton
John Dalton came up with specif value to the mass of each atom as part of his research. He compared the mass of each atom to the mass of hydrigon. The model that he came up with was commenly known as the billard model. -
Ernest Rutherford
He was born in New Zealand and studied at the University of New Zealand and the University of Cambridge. His theory proposed that the atom had a central nucleus that was positive and was surrounded by negative electrons. His model showed that most of the mass was found in the nucleus and the rest was empty space. He conducted an experiment (the gold foil experiment) that showed us that the atom had a concentrated positively charged nucleus that contained a large mass. -
J. J. Thompson
J. J. Thompson identifys another atomic particle in which he named the electron. His discovery showed that atoms were not indivisible. Thompson came up with the 'plum pudding' model which suggests an atom has a soft, positive charged centre and negatively charged electrons which were embedded around it. -
Niels Bohr
Niels was a Danish physicist and his study at his institute has led to a more complex understanding of atomic structure. Bohr's atomic model gave us a more complex view of Ernest Rutherford's model. He assumed that electrons that travel in orbits that are determined by the atom's structure. Each orbit had an energy level/shell which had a set size (capacity) and energy. -
James Chadwick
James Chadwick makes the discovery of another atomic particle located in the nucleus and that weighed the same as a proton. He called it the neutron because it had no charge and it was shortened for neutral proton. -
Higgs Boson
The Higgs Boson particle was thought to be discovered by a Scottish scientist Peter Higgs in the 1960's. It is thought to have played a fundamental role in the creation of the universe. It is thought to carry particles of the Higgs field which gives mass to all matter
