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John Dalton
John Dalton is a British chemist who learned by using experiments and the scientific method. He believed all substances were either pure or a combination of pure substances.His postulates were as follows:
1.Matter is made up of atoms.
2.Atoms can be rearranged, but can't be created or destroyed.
3.All atoms of a given element are identical.
4.Atoms of different elements differ in mass and other properties.
5.In a given compound, different types of atoms are always present in the same proportions -
J.J. Thomson
He discovered the electron. He is also behind the Cathode ray tube, and the Plum pudding model. Cathode rays were coming out of atoms; therefore, they were part of the atom. The atom, however, had both positive and negative parts. These parts were held together loosely. He put the ideas together, and described it as Plum pudding. The atom was like the pudding; electrons were like the pieces of plum, and the dough was positively charged. -
Ernest Rutherford
He was a British physicist, and a student of J.J. Thomson. He studied the alpha radiation particles when they were newly discovered. He found that the nucleus was small, solid, and positively charged. He also found that the nucleus has most of the mass of the atom. Also that electrons are outside the nucleus, and they orbit the nucleus like planets orbit the sun. -
Niels Bohr
He was a Danish physicist, and he developed the Bohr model of the atom. He was a student of Rutherford. He was the man who described the fact that electrons can only be in specific energy levels, like books on a bookshelf. He also said that electrons move to a higher "shelf" by absorbing a quantum (a photon). -
Erwin Schrodinger
He was the man who studied the Wave Equation of the electron. He found that electrons are both like particles, and live like waves. He though equation could predict location and shape of electron "orbitals."
