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400 BCE
Democritus
Created the three rules that all atoms will always follow.
1. Atoms cannot be cut
2. Atoms are all made of the same material but in different shapes and sizes
3. Atoms were infinite and are always moving and are always capable of joining together -
John Dalton
All matter is made of atoms and even though his theory is two centuries old its still accepted to this day. His theory also states that chemical reactions are a rearrangement of atoms and that if two or more atoms are combined it forms a compound. -
Dmitri Mendeleev
Created the first-ever periodic table which he organized atoms by atomic number as by property similarities. -
Eugene Goldstein
Discovered the proton using experiments that would attract electrons of atoms to a positively charged electrode. -
J J Thomson
Discovered the electron and then created the pudding model where the atom is made of protons and surrounded by electrons. -
Ernest Rutherford
Rutherford's model/experiment overthrew Thomson's model, his experiment proved that the atom had a heavy nucleus. He did this using his gold experiment which would measure how a alpha particle scattered across a metal foil. -
Niel Bohr
As protons and electrons orbit the nucleaus of the atom and switch orbits/paths it emits a burst of light. -
Max Planck
Created the quantum theory which describes compounds at the smallest energy scales (atoms and subatomic particles). His theory helped to explain the process that all atoms do. -
Robert Millikan
Robert conducted an experiment that figured out the charge size of electrons he also figured out the smallest unit of charge. -
Erwin Schrodinger
Created an equation that could predict/find where a electron orbited around the nucleus of an atom. -
Werner Heisenberg
Created mathmatic equations that would help us to be more precise when measuring exactly where protons, electrons, and nuetrons were located in an atom. -
James Chadwick
He discovred particles with a neutral charge now known as neutrons.
