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400 BCE
Democritus
Matter is composed of empty space through which atoms move. Atoms are solid, homogeneous, indestructible and indivisible. Different types of atoms are different shapes and sizes. Different properties would be due to size, shape, and movement. -
340 BCE
Aristotle
The most influential philosophers who wrote extensively on many subjects such as politics, ethics, nature, physics, and astronomy. Not all of them have been found because they have been lost throught time. -
Automobile was invented
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Revolutionary War
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Antonie Lavosier
Lavosier performed some of the first quantitative chemical experiments which led to the statement of the law of conservation of mass. https://www.youtube.com/watch?v=41lACsJcbWQ -
Joseph Proust
Proust came up with the constant composition, stating that chemical compounds always combine in constant proportions -
William Crookes
Noticed a flash produced by some form of radiation striking a light-producing coating that had been applied to the end of the tube which then discovered the cathode ray. -
John Dalton
All matter is composed of tiny atoms. Atoms of a given element are indentical, same size, mass, and chemical properties. Atoms can't be created or destroyed. Different atoms combine in simple whole number ratios to make compounds. https://www.youtube.com/watch?v=OUoV--CuLDA -
Amadeo Avagadro
He made contributions to molecular theory, including what is known as Avogadro's law. which states that equal volumes of all gases, at the same temperature and pressure, have the same number of molecules. -
War of 1812
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CIvil War
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Assassination fo Abe Lincoln
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Thomas Edison invented the light bulb
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J.J. Thomson
He was carefully measuring the effect of both magnetic and electric fields on a cathode ray, then he was able to determine the charge-to-mass ratio of the charged particle. He found that the mass of the charged particle was much less than that of a hydrogen atom. -
Henri Becquerel
On accident, he discovered that the uranium salts spontaneously emitted a penetrating radiation that could be registered on a photographic plate. https://www.youtube.com/watch?v=aU_Lch2Dauo -
Madame Curie
She discovered radioactivity, and conducted pioneering research on radioactivity. -
Max Planck
He searched for an explanation by studying the light emitted from heated objects which made him find that matter can gain or lose energy in small specific amounts. This made him find the quantum theory. https://www.youtube.com/watch?v=R9sMxEnbha0 -
Albert Einstein
Albert proposed that a photon is a particle of electromagnetic radiation with no mass that carries a quantum of energy, therefore electromagnetic radiation has both wavelike and particle-like natures. -
Robert Millikan
Determined the charge of electrons. -
Ernest Rutherford
Ernest studied how positive alpha particles interacted with solid matter. He thought that most of the fat-moving particles along witht eh large alpha particles to pass through gold atoms, but with a slight deflection by electrons in the gold atoms. -
Titanic sunk
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Henry Moseley
He discovered that atoms of each element contain a unique positive charge in their nuclei which means the number of protons in an atom identifies it as an atom of a particular element. -
Niels Bohr
He made a quantum model for the hydrogen atom. -
Jouis deBroglie
He proposed an idea that eventually accounted for the fixed energy levels of Bohr’s model. -
Erwin Schrodinger
Erwin furthered the wave-particle theory proposed by de Broglie. -
Werner Heisenberg
Werner concluded that it is impossible to make any measurement on an object without disturbing the object. -
James Chadwick
He thought nucleus also contained another subatomic particle, a neutral particle called the neutron. https://www.youtube.com/watch?v=HnmEI94URK8 -
Martin Luther Kings I Have a Dream speech
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Terrorist attack on September 11.
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Death of Osama Bin Laden
