Democritus proposed the first idea of the atom. Substances made up of invisible, indestructible particles.
Proposed Atomic Theory
This led to many discoveries in the Atomic Theory
Discovered electron to determine the charge to mass ratio of the electron.
Cathode Ray Tube Experiment
Discovered negatively charged electrons
Plum Pudding Model
Concluded the atom is empty space with a small positive nuclear core
Gold Foil Experiment
Tried to answer question: Why arent electrons pulled into the nucleus?
Hypothesis- If waves can behave like particles, then particles can behave like waves.
Electrons can act like waves
Heisenberg's Uncertainty Principle
It's impossible to know the position and velocity of an electron at the same time.
Electrons move to fast to track
Schrodinger's Wave Equation
Treated the electron like a wave
Developed an equation to find the electron in any given place around the nucleus
Solution to this equation was a quantum number
Discovered the neutron