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Oct 7, 1001
Democritus
First person to give the thought of the particle. Used the word atomos to describe the particle. This was around 400 b.c. Atom was indivisible and indesrtuctable to him. -
Period: Oct 7, 1001 to
Atom
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Robert Boyle
Robert Boyle replaced the idea that everything was made up of either earth, wind, fire, or air. He proposed the first of the elements in his book called “Sceptical Chymist”. -
Antoine Lavoisier
He came up with the law of conservation, which is that matter can’t be made or destroyed -
John Dalton
Matter is simply composed of atoms of different weight and it combined in ratios by weight. Believed atoms were indivisible, atoms of the same elements are indentical to eachother, atoms combine in whole numbers and they can't be destroy -
Dmitri Mendeleev
He created the first periodic table of elements arranging elements by atomic mass. -
Eugen Goldstein
Used canal rays that had electrical and magnetic properties opposite of an electron, led to discovery of protons. -
JJ Thomson
Discovered the electron and proved that atoms were divisible by using a a plum pudding model of an atom. -
Max Planck
He introduced what would known as quantum theory m stating the electromagnetic energy could only be emitted in quantized form. -
Robert Millikan
The measure the charge of a single electron. known as elementary charge one of the fundamental physical physical constants. He used a Milikan's oil-drop apparatus to discover this. -
Ernest Rutherford
He was known for father nuclear physics and developed the theory for the structure of the atom. -
Henry Moseley
He proposed that the relationship was a function of the positive charge on the nucleus -
Neils Bohr
Bohr explained what happens inside an atom and developed a picture of atomic structure. -
Erwin Schrodinger
He described how electrons move in a waveform, and developed the Schrodinger equation which describes the quantum state of a system changes with time. -
James Chadwick
Discovered the neutron
