September 30, 2021
For educational institutions
History of an Atom
⟶ Updated 6 Nov 2017 ⟶
List of edits
Democritus was born.
Antoine Lavoisier was born.
John Dalton was born.
J.J. Thomson was born.
Ernest Rutherford was born.
Robert Millikan was born.
Marie Curie was born.
James Chadwick was born.
Max Planck was born.
Albert Einstein was born.
Niels Bohr was born.
Louis De Broglie was born.
Erwin Schrodinger was born.
Werner Heisenberg was born.
Antoine Lavoisier found that when mercury oxide is heated its weight decreases.
John Dalton revealed the concept of Dalton’s Law of Partial Pressures.
J.J. Thomson discovered the electron and determined that it was a component of the atom. He demonstrated that cathode rays were negatively charged.
J.J. Thomson discovered neon was composed of two different kinds of atoms, and proved the existence of isotopes in a stable element.
Ernest Rutherford discovered radioactivity.
Ernest Rutherford demonstrated that there were at least two distinct types of radiation: alpha radiation and beta radiation.
Robert Millikan succeeded in precisely determining the magnitude of the electron's charge.
John Dalton was the first scientist to explain the behavior of atoms in terms of the measurement of weight.
Antoine Lavoisier named the elements carbon (1772), hydrogen (1783), oxygen (1779), and sulfur (1774).
Marie Curie successfully produced radium as a pure metal, which proved the new element's existence beyond a doubt.
James Chadwick proved the existence of the neutron.
Max Planck introduced the theory of quanta. Radiation consists of quanta with specific energies determined by a new fundamental constant, thereafter called Planck's constant.
Albert Einstein devised a mathematical method of calculating the size of atoms and molecules.
Niels Bohr proposed a theory for the hydrogen atom based on quantum theory that energy is transferred only in certain well-defined quantities.
Louis De Brogile introduced the idea that particles, such as electrons, could be described not only as particles but also as waves.
Democritus expanded the atomic theory of Leucippus.
Erwin Schrödinger formulated a wave equation that accurately calculated the energy levels of electrons in atoms.
Werner Heisenberg formulated a type of quantum mechanics based on matrices and proposed the "uncertainty relation", setting limits for how precisely the position and velocity of a particle can be simultaneously determined.
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