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Democritus formulates his atomic theory; his atomic theory is the first of its kind, and says that all things are made up of indivisible, invisible, always moving, and unique particles.
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Democritus' Lifetime
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Antoine Lavoisier is born in Paris, France.
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Antoine Lavoisier's Lifetime
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John Dalton is born to a quaker family in Cumberland, England
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Dalton built upon Democritus’ atomic theory, which had since been unchanged or rebuffed for two millennia.
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The elements oxygen and hydrogen are officially named by Antoine Lavoisier
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Antoine Lavoisier dies at the age of 50 in Paris, France; his spouse dies the same year
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John Dalton announces his famous atomic theory that built upon Democritus’ theory to the scientific community.
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John Dalton dies in Manchester; 40,000 people attend his funeral.
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JJ Thomson is born in Cheetham Hill, England
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Thomson determined that matter was made up of miniscule particles - smaller than atoms, called ‘corpuscles,’ although the name never stuck. They are what we know of as electrons, and his discovery upended the current theory that the atom was the smallest unit in existence. He also determined that electrons were negatively charged, but recognized that because matter is neutrally charged, there must be a positive charge within each atom to negate the electron’s effects.
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Max Planck is born in Kiel, Holstein, Gemany
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He is considered by the scientific community to be founder of quantum theory. He presented a theoretical explanation as to the spectrum of radiation emitted by a glowing object. He believed that the walls of an object could have a series of resonators that oscillated at different frequencies; essentially leading him to believe that energy does not flow in a steady continuum.
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Marie Curie is born in Warsaw, Poland; at the time it was part of the Russian Empire
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She discovered the elements radium and polonium, and was influential in the medical fields for her experiments relating to radiation. She predicted that atoms stored immense energy inside themselves, and that radioactive energy came from within atoms, and that the Earth was already completely covered in it. She invented the word ‘radioactivity’ for her findings.
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Robert Millikan was born in Morrison, Illinois
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He determined the exact charge of an electron in 1909, and created a way of calculating the mass of the electrons and positively charged portions of the atom. He discovered that the mass of an electron - which is always the same, is 1000 time smaller than the smallest atom discovered at the time.
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Ernest Rutherford was born on a farm in a New Zealand village, the fourth of twelve children.
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He was responsible for a series of outstanding discoveries in the fields of radioactivity and nuclear physics. Specifically, he discovered the existence of alpha and beta rays, produced the laws of radioactive decay, and hypothesized the nuclear structure of the atom. His hypothesis of the atom is the most accurate, with protons in the nucleus and electrons orbiting them.
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Einstein devised a way of predicting the sizes of atoms and molecules. Along with many other scientific contributions, he developed the quantum theory of heat, and the theory of relativity, and some other stuff.
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He made remarkable contributions to the fields of quantum theory, and devised the bohr model, which assisted in the portrayal of atomic structure and is still in use in modern day. He also proposed the idea of the nucleus as a liquid drop.
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He provided the basis for bohr’s famous atomic model by devising a model to find where an electron of an atom would be at any given time.
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James Chadwick is born in bollington, England
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In 1932 his research lead to him discovering that inside the nucleus of an atom were neutrons, which contained a neutral charge, unlike protons or electrons. This discovery was pivotal to the later discovery of nuclear fission, which would later assist in the building of atomic bombs.
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His ideas assisted in the complete development of the wave mechanics theory - a theory that stated that electrons can act like both particles and waves; waves produced by electrons constrained in the orbit around the nucleus of an atom, set up a standing wave of energy, frequency, and wavelength.
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His contributions to physics was the famous principle of uncertainty, which stated that the determination of the position and momentum of a non-static particle contain errors that cannot be less than the quantum constant, and although the errors are negligible on a human scale, they cannot be ignored on a molecular or scientific scale.
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Began his experiments; determined the exact charge of an electron and created a way of formulating the mass of the electrons and positively charged protons in an atom.
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