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340
Aristotle
B.C. NOT A.D. DAY AND MONTH UNKNOWN.
Aristotle proposed his atomic theory in 340 bc.
He believed that there were 4 elements and no empty space.
He was saying that all things are made up of 4 elements. -
400
Democritus
BC. Democritus is before Aristotle. He is the first person to come up with the atom. He found out that everything is made up of small parts. This revolutionized everything because people started to understand what things are made up of, but he didn't accept that everything was made out of atoms. -
John dalton
John dalton did not reshape the atom, but he came up with an atomic theory that is still correct.
What this did was change the way atoms were looked at. Also said they are solid spheres -
Antoine Lavoisier
He came up with the law of conversions. He also started conversations on what an atom really is. Mass cannot be created or destroyed. -
J.J. Thomson
He discovered that atoms had negative charges but thought that they were just floating inside the atom. Thus he discovered electrons.
He also proposed that the electron was 1000 times smaller then the atom.
He influenced Robert Millikan. -
Max Planck
He was the one that started the quantum theory. The theory was packets of energy.
The quantum theory later influenced the atom and advanced the atom.
Was affected by Robert Millikan. -
Robert Millikan
Measured the charge of an electron with the oil drop expirament.
Robert also inspired max Planck. -
Ernest Rutherford
He proposed that electrons circle the nucleus like planets to the sun.
This changed what they thought about how electrons circled. Also did the gold foil expirement. -
Niels Bohr
He contributed the fact that the atom had electrons orbiting the nucleus.
The difference between this model and the older ones was that this has electrons orbiting differently. Because they are in discret levels. -
Henry mosely
He worked with Bohr inorder to create the atomic numbers. Thus creating moselys law. -
Erwin schrodinger
He disagreed with what dalton said so he created his own.
Erwin ended up influencing the quantum atom model.
He achieved this by trying to measure the distance between the electron and nucleus. -
Werner Heisenberg
He discovers some uncertaintys in the quantom model. Because of this he found flaws in bohrs model. Helped create nukes. Good friends with bohrs. -
James Chadwick
James Chadwick discovered the neutron and proved its existence.
He made it known to this day the neutron existence.
