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John Dalton, Solid Sphere Model
In 1803, John Dalton's experiments with chemicals suggested that matter is made of particles. He did not know what these particles look like and thought they may be like tiny solid spheres. -
J. J. Thompson, Plum Pudding Model
J.J. Thompson realized that atoms have electrons and that these electrons have a negative charge. So, he thought matter itself must have a positive charge. His model is called the plum pudding model because it looks like pudding with electrons on its surface. -
Ernest Rutherford, Nuclear Model
In an effort to look at the inside of the atom, Ernest Rutherford fired alpha rays at gold atoms. Much of his experimentation had results different than what he expected. He learned that negatively charged electrons orbit a positively charged center and that the electrons are relatively far from the center. In 1919, Rutherford discovered that the atom's center is made of distinct particles. -
Niels Bohr, Bohr (Planetary) Model
Niels Bohr's model had electrons orbiting around the nucleus in such a way that they can't hit the nucleus. Bohr also proposed rules that attempt to explain how atoms do behave. 1) Electrons are only able to orbit at the distances they are allowed from the nucleus and can only exist in one orbit at a time. 2) When an electron moves from higher orbit to a lower orbit, an atom emits energy. When an electron moves from a lower to a higher orbit, an atom absorbs energy. -
Ervin Schrodinger, Quantum Mechanics Model
Schrodinger's model is able to mathematically predict approximately where an electron should be in its orbit. This model is the most current. -
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