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300
Aristotle (300 BC)
He declared that there were only four elements of matter being fire, air, water and earth and all matter is made up of these elements. He also said that matter had four properties that were hot, cold, dry, and wet. -
440
Democritus (440 BC)
Atoms are solid homogeneous, indestructible, and indivisible. Different atoms have different shapes and sizes. -
Piano was invented
Bartolomeo Cristofori -
Antonie Lavosier
He disproved the idea of the phlogiston theory and stated the Law of Conservation of Mass. Developed a system of naming chemical compounds and named the element hydrogen. He discovered that water was a compound and not an element which was popular belief. He also wrote the first chemistry textbook. -
Joseph Proust
Developed the law of definite proportions -
First vaccination is invented
Edward Jenner https://www.youtube.com/watch?v=Zcftgu1Dwk4 -
John Dalton
Developed Dalton's atomic theory. Also said that all atoms of an element are identical with the same size, mass, and chemical properties. Atoms combine to form compounds and in a chemical reaction, atoms are separated, combined, or rearranged. -
The War of 1812 Begins
War between the United States and Great Britain -
Amedeo Avogrado
Developed Avogrado's Law. -
John Wilkes Booth assassinates Abraham Lincoln
Assassination of Abraham Lincoln -
William Crookes
Discovered thallium and created the "Crookes tube" which led to the discovery of cathode rays. -
Automobile is invented
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J.J. Thomson
Discovered the electron. He also developed a plum pudding model that proposed that negatively charged electrons were spread out in a uniform positive charge. -
Henri Becquerel
Discovered spontaneous radioactivity -
Marie Curie
Discovered polonium and radium after Henri Becquerel discovered radioactivity. -
Albert Einstein
E=mc^2, He explained the photoelectric effect, that electromagnetic radiation has both wavelike and particlelike natures which explains photons. -
Robert Millikan
Accurately determined the charge carried by an electron using the "falling-drop method," and verified Einstein's E=mc^2 -
Ernest Rutherford
He set up an experiment that led him to discover the nucleus and to disprove Thomson's plum pudding model of the atom. -
Henry Moseley
He discovered that atoms of each element contain a unique positive charge in their nuclei. He developed a more accurate positioning of elements in the periodic table by determining their atomic numbers. -
Max Planck
Discovered concept of the energy quanta: the emitted radiation consists of quanta specific energies determined by the Planck constant -
Niels Bohr
Developed Bohr's Theory, which could explain why atoms emitted light in fixed wavelengths -
Werner Hiesenberg
Developed his uncertainty principle at age 23 which states that the better you know the position of a particle, the less you know the momentum and vice versa. This was part of the start of quantum mechanics. -
Erwin Schrodinger
Formulated a wave-equation that accurately gave the energy levels of atoms -
Louis de Broglie
Discovered the wave nature of electrons -
James Chadwick
Discovered the neutron -
The barcode is invented
Norman Woodland -
Email is invented
Shiva Ayyadurai -
Amazon is founded
Jeff Bezos https://www.youtube.com/watch?v=98BIu9dpwHU -
Planes crash into the twin towers in NY
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Osama bin Laden is killed
