-
345
Aristotle BC
+Thought all materials on earth were not made of atoms but the 4 elements
+ -
460
Democritus BC
+Developed the idea of atom +Modeled it with a solid ball +Didnt know about a nucleus or electrons, just that everything is made of atoms -
Dalton
+Proposed an "atomic theory" with spherical solid atoms based upon measurable properties of mass
+Made careful quantitive measurements which allowed the compositions of compounds to be determined w/ accuracy
+tiny, indestrutive particles & each had a certain mass, size, and chemical behavior that was determined by what kind of element they were -
Thomson
J.J Thomson discovered the electron using the cathode tray tube in 1904
Thomson thought the atoms was a sphere of positive force with eletrons around it.
a sphere of positive force with electron -
Rutherford
+Descovered the nucleus
+Theory was that the atom has a positive nucleus w/ negative electrons orbiting around -
Bohr
+Created Atomic Model
+Applied quantum theory to Rutherfords atomic structure w? assuming that electroms travel in stationary orbits defined by their angular momentum -
Heisenberg and Schrodinger
- Descovered th "Uncertanty Principle"
- Caculated the behavior of electrons +Looked like a cloud
