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John Dalton
Dalton had decided that matter is composed of units called atoms,
-Elements are made from extremely small particles called atoms.
-Atoms of a given element are identical in size, mass, and other properties; atoms of different elements differ in size, mass, and other properties.
-Atoms can't be subdivided, created, or destroyed.
-Atoms of different elements combine in simple whole number ratios to form chemical compounds.
-In chemical reactions, atoms are combined, seperated, or re-arranged. -
J.J. Thomson
Description: Thomson concluded that the atom was a solid mass. Thomson had discovered the electron, the universal building blocks of atoms. Otherwise known as "corpuscles." He discovered this by the Cathod Ray experiment.The classic means of measuring the charge and mass of the electron was invented by him. In 1906, he demonstrated how hydrogen has one electron. -
Rutherford
Rutherford had discovered that the atoms are mostly empty space, not according to what Dalton had said. Rutherford performed the gold foil experiment which lead him to his discovery. He had aimed alpha particles(helium atoms) at gold foil to find out that most had passed through and a few were deflected. He had also discovered that the atom has a dense, positively charged core. -
Bohr
Bohr had discovered that electrons are in specific rings. They can move from one ring to another, but thay can't be in between two rings. He had concluded that:
-Electrons in atoms orbit around the nucleus
-Electrons can only gain or lose energy by jumping from one orbit to another.
-Electrons orbit stably in certain orbits that are certain distances away. -
Chadwick
Chadwick had discovered you can divide the nucleus between protons and neutrons. He had also discovered the neutron is located in the nucleus, which had been proposed by Rutherford. Chadwick had discovered the neutron was a neutral charge because it had not been affected by proximity to a magnetic field. -
Modern Model
This model can help discover the highest probabilty to find an electron on the electron cloud.
Protons and neutrons are located in the nucleus of the atom. The nucleus is small compared to the overall size of the atom. The majority of the space of an atom is the space in which the electrons move around.
Electrons are attracted to the protons in the nucleus by the force of attraction between particles of opposite charge.
