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John Dalton
Dalton thought that atoms were like smooth, hard balls that could not be broken into smaller pieces.
"I used the book for this." -
JJ Thomson
He described an atom that change had electrons scattered throughout a ball of positive charge-something like seeds in a watermelon. "I used the book for this." -
Neils Bohr
Bohr suggested that electrons are found only in specific orbits around the nucleus. The orbits in Bohr's model look like planets orbiting the sun or the rings of a tree. Each possible electrons orbits in Bohr's model has a fixed energy.
"I ued the book for this one." -
Earnest Rutherford
Rutherford overturned Thomson's model with his well-known gold foil experiment in which he demonstrated that the atom has a tiny, heavy nucleus. Rutherford designed an experiment to use the alpha particles to see the paths of some particles would bend, deflect because the positive charge was thought to be spread in the gold atoms.
"I used the book for this one." -
Erwin Schrödinger
Erwin Schrödinger, an Austrian physicist, took the Bohr atom model one step further.Schrödinger used mathematical equations to find the likelihood of an electron in a certain position. This atomic model is known as the quantum mechanical model of the atom.
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James Chadwick
James Chadwick bombarded beryllium atoms with alpha particles. An unknown radiation was produced. Chadwick interpreted this radiation as being composed of particles with a neutral electrical charge and the approximate mass of a proton. This particle became known as the neutron.
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