Chemistry Events

  • 100

    Democritus

    Democritus
    460-370 B.C.
    Proposed the concept of the atom
    -Matter is composed of empty space through which atoms move.
    -Atoms are solid, homogeneous, indestructible, and indiviseble.
    -Different kinds of atoms have different sizes and shapes.
    -The differing properties of matter are due to the size, shape, and movement of atoms.
    -Apparent changes in matter result form changes in the groupings of atoms and not from changes in the atoms themselves.
  • 110

    Aristotle

    Aristotle
    384-322 B.C.
    Rejected the concept of the atom
    -One of the most influential philosophers.
    -Wrote extensively on may subjects, including politics, ethics, nature, physics, and astronomy.
    -Most of his writings have been lost through the ages.
  • Sep 24, 1492

    Christopher Columbus

    Christopher Columbus
    VideoIn this year Columbus sailed the oceans and found the Americas
  • John Dalton

    John Dalton
    1766-1844
    Breakthough in our understanding of matter because of atomic theory.
    -All matter is composed of extremely small particles called atoms.
    -All atoms of a given elemtent are identical, having the same size, mass, and chemical properties. Atoms of a specific element are different from those of any other element.
    -Atoms cannot be created, divided into smaller particles, or destroyed.
  • John Dalton Continued

    John Dalton Continued
    -Different atoms combine in simple wholenumber ratios to form compounds.
    -In a chemical reaction, atoms are separated, combined, or rearranged.
  • The American Revolution

    The American Revolution
    1775-1781 the Americans fought against their mother country of Great Britian and won after a long bloody war.
  • Joseph Proust

    Joseph Proust
    1754-1826
    Proved the idea that every pure chemical compound consists of elements in a definite proportion. Developed the use of hydrogen sulfide as a reagent. Gave results of his chemical analyses in terms of percentage weights.
  • Antoine Lavoisier

    Antoine Lavoisier
    1743-1794
    Compiled a list of the 23 elements known at the time.
  • The Louisiana Purchase

    The Louisiana Purchase
    VideoThe purchase of 828,000 square miles of land that include Iowa!
  • Amedio Avogadro

    Amedio Avogadro
    1776-1856
    Determined the volume of one mole of a gass. 6.02 X 10^23
  • William Crookes

    William Crookes
    1832-1919
    Noticed a flash of light within one of the tubes in his darkened laboratory
    -flash was a produced because radiation was striking a light-producing coationg that had been applied to the end of the tube.
    -Figured out these flashes where rays traveling from the cathode to the anode within the tube.
    -Called a cathode ray
    -this discovery lead to the television and computer monitor
  • The Civil War

    The Civil War
    The war between the north and the south over slavery lasted from 1861 to 1865. In the end the north won and slavery was abolished.
  • Abraham Lincoln

    Abraham Lincoln
    Lincoln was assassinated in this year by John Wilkes Booth at Ford's Theatre in Washington D.C.
  • J.J. Thomson

    J.J. Thomson
    1856-1940
    Experiments with cathode ray tube to determine the ratio of its charge to its mass
    -Plum pudding atomic model proposed that negatively charged electrons were distributed throughout a uniform positve charge
  • Henri Becquerel

    Henri Becquerel
    1852-1908
    Studied minerals that emit light after being exposed to sunlight. Discovered that phosphorescent uranium salts produce spontaneous emissions that darken photographic plates even when not exposed to light.
  • Max Planck

    Max Planck
    1858-1947
    Studied the light emitted from heated objects.
    Matter can gain or losse energy only in small, specific amounts called quanta. Quantum is the minimum amount of energy that can be gained or lost by an atom.
  • Marie Curie

    Marie Curie
    1867-1934
    Isolated the components emitting the rays in Becquerel's mineral sample. Darkening of plates was because of uranium atoms persent in the mineral sample when rays where emitted. Named the process by which materials give off such rays as radioactivity. Identified the two new elements polonium and radium because of radioactivity.
  • Albert Einstein

    Albert Einstein
    1879-1955
    Electromagnetic radiation has both wavelike and particlelike natures. as beam of light has many wavelike charateristics, it also can be thought of as a stream of tiny particles, or bundles of energy, called photons, photons are particles of electromagnetic radiation with no mass that carries a quantum of energy
  • Robert Millikan

    Robert Millikan
    1868-1953
    Determined the charge of an electron
  • Ernest Rutherford

    Ernest Rutherford
    1871-1937
    His experimenting proved Thomson's plum pudding model wrong.
    -most of an atom consists of electrons moving rapidly through empty space. The electrons move through the available space surrounding the nucleus and are held within the atom by their attraction to the positively charged nucleus. Very small and dense nucleus.
    -The nucleus contains positively charged particles called protons
  • Henry Moseley

    Henry Moseley
    1887-1915
    Discoved that atoms of each element contain a unique positive charge in their nuclei. The number of protons in an atom identifies it as an atom of a particular element. The number of protons in an atom is referred to as the element's atomic number.
  • Niels Bohr

    Niels Bohr
    1885-1962
    Proposed a quantum model for the hydrogen atom that seemed to answer this question. Model also correctly predicted the frequencies of the lines in hydrogen's atomic emission spectrum. Related the hydrogen atom's energy states to the motion of the electron within the atom
  • Louis de Broglie

    Louis de Broglie
    1892-1987
    Thought that Bohr's quantized electron orbits had characteristics similar to those of waves. The de Broglie equation predicts that all moving particles have wave characteristics.
  • Werner Heisenberg

    Werner Heisenberg
    1901-1976
    It is impossible to make any measurement on an object without disturbing the object. The Heisenberg uncertainty priciple is that it is fundamentally impossible to know percisely boht the velocity and position of a particle at the same time.
  • Erwin Schrodinger

    Erwin Schrodinger
    1887-1961
    Treated the hydrogen atom's electron as a wave. The quantum mechanical model of the atom is an atomic model in which electrons are treated as waves, also called the wave mechanical model of the atom. Model attempts to describe the electron's path around the nucleus.
  • James Chadwick

    James Chadwick
    1891-1974
    Nucleus also contains another subatomic particle, called a neutron that whas a neutral particle
  • Adolf Hitler

    Adolf Hitler
    Committed suicide after it became evident that he would not take over the world after causing WWII.
  • Assassination of John F. Kennedy

    Assassination of John F. Kennedy
    In this year JFK was assassinated by Lee Harvey Oswald
  • Apollo 11

    Apollo 11
    VideoApollo 11 was the first moon landing ever made and this was done by the United States of America.
  • September 11, 2001

    September 11, 2001
    Video4 american planes where taken controll of by terrorists. This started the war against terror.
  • Death of Osama bin Laden

    Death of Osama bin Laden
    VideoDied when American soildiers found where he was hiding and shot him while they searched the house.