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Brownian Motion
In 1827, Dr. Robert Brown did an experiment where he suspended smoke particles in water and observed their erratic motion. This led to the understanding that matter is made up of smaller particles they called atoms. -
Gas Discharge Tube Experiment
In 1869, Physicist William Crookes placed gas in a tube and ran an electric current through it. The gas inside the tube separated into negative and positive pieces. This led to the understanding that there are positive and negative pieces within an atom. -
Gold Foil Experiment
In 1911, a physicist named Ernest Rutherford shot positively charged alpha particles through a thin sheet of gold foil. Every so often, one of the alpha particles would bounce back. This led to the understanding that the positive pieces of an atom are concentrated in the middle of the atom. -
Discrete Spectra Experiment
In 1913, scientists discovered that different gases have different emission spectrums. This means that electrons have to be orbiting at specific energy levels. This led to the Bohr model of the atom. -
Mathematical Experimentation with Electrons
In 1926, Erwin Schrödinger used mathematical formulas to calculate the probability of finding the position of an electron. His famous calculations are what led to the Quantum Model of the Atom. -
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Quantum Model of the Atom
The Quantum model explains that electrons are standing waves of probability surrounding the nucleus. The Quantum Model of the Atom is our best understanding about atoms to this point in time. -
Double Slit Experiment
In this experiment, scientists shot electrons through two closely spaced slits. They expected to see a particle pattern on the other side, but they observed that the electrons behaved like waves when passing through the slits. This means that electrons have wave-particle duality and solidified our understanding of the Quantum Model of the Atom.
Dr. Quantum's Explanation
