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Antoine Lavoisier developed an experimentally based theory of the chemical reactivity of oxygen and coauthored the modern system for naming chemical substances.
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Joseph Proust created the law of definite proportions. This law states that the relative quantities of any given pure chemical compound’s constituent elements remain invariant, regardless of the compound’s source.
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John Dalton created the first Atomic Theory of Matter.
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Dmitri Mendeleev developed the periodic classification of the elements; it is arranged by increasing atomic weight.
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Henri Becquerel discovered radioactivity by experimenting with uranium and other substances.
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Marie Curie's work led to the discovery of polonium and radium, and she developed x-rays.
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Max Planck created quantum theory.
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Robert Millikan found great discoveries in the study of elementary electronic charge and the photoelectric effect. He performed experiments in order to find the charge of an electron.
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Ernest Rutherford was a key figure in the study of radioactivity and developed his own theory of atomic structure. His theory stated that most of an atom is made up of empty space.
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Henry Moseley proved that every element is uniquely determined by the number of protons it has.
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Niels Bohr proposed a model of the atom in which the electron was able to occupy only certain orbits around the nucleus. This atomic model was the first to use quantum theory.
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Louis de Broglie discovered the wave nature of electrons and suggested that all matter have wave properties.
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Erwin Schrödinger built upon the wave theory of matter. He created the Schrödinger equation, which explained the evolution of the wave function-a quantity that describes the wave properties of a particle.
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Werner Heisenberg discovered the uncertainty principle, which states that the position and the momentum of an object cannot both be known exactly.
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Jame Chadwick is famously known for the discovery of neutrons.
