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Sep 28, 1000
Aristotle
Thought if you break a piece of matter again and again, it would at some time stop, and end with a small piece of matter. -
Sep 28, 1000
Democritus
442 B.C.
Said everything is composed of atoms.
They are solid, indestructable, and homogeneous.
They are different sizes and shapes.
Changing in groupings of atoms, not the atom itself. -
Antonie Lawosier
Named Oxygen.
Proposed law of conservation of mass and the combustion theory. -
Joseph Proust
Proposed law of constant composition. -
John Dalton
Formed atomic theory.
Named Thallium in 1861.
First to identify Helium in 1895.
Said all matter is composed of atoms.
Each element has identical atoms.
Can't be created, divded into smaller particles, or destroyed. -
Amadeo Avagadro
Proposed Avogadro's hypothesis. -
Lincoln Murdered
He was killed by John Wilkes Booth, when he was at the theater with his wife. -
William Crooks
Identified that cathrode rays travel in straight lines. -
Henri Becquerel
Discovered radio-activity.
Discovered some chemicals spontaneously decompose and give off penetrating rays. -
J.J. Thomson
Discovered electron.
1904- suggested model of the atom. -
Madame Curie
Studied Uranium and Thorium.
Called the spontaneous decay process radioactivity. -
Max Planck
Used idea of quanta to explain glowing matter. -
Panama Canal Construction Begins
48 mile ship canal, that joins the Atlantic Ocean.
1904-1914 -
Robert Millikan
7 year study on the electron; discovered its charge. -
Ernst Rutherford
Won the Nobel Prize
Studied charged alpha particles.
In 1920 proposed exsistence of the 3rd atomic particle, neutrons. -
Henry Moseley
Discovered energy of x-rays increased in a linear fashion with each element in the table. -
Albert Einstein
Stimulated emission-physical process that makes possible the maser and the laser; same frequency. -
US Joins WWI
After the Japenese bombed Pearl Harbor; we got mad and joined -
Niels Bohr
Explained atomic structures.
Atomic model built up of successive orbital shells of electrons. -
Louis deBroglie
Said electrons had a dual nature- similar to both particles and waves. -
Werner Heisenberg
First to describe atoms.
Proposed principle of indeterminacy (can't know the position and velocity of an atom). -
Invention of the Electric Razor
Jacob Schick (born in Ottumwa, Iowa) -
Erwin Schrodinger
Introduced term 'wave mechanics'. -
James Chadwick
Used alpha particles to discover a neutral atomic particle.
The nucleus also contains a neutron; led to atomic bomb. -
Japenese Bomb Pearl Harbor
Japenese were trying to prevent us from interfering with their army.
We were attacked by 353 Japenese. -
AIDs Discovered
Affects the immune system.
Discovered by the US Centers for Diesease Control in 5 homosexual men, in LA. -
Cold War Ends
Started in 1946
Between Communists and the Western World -
Scientist Clone 1st Human Embryo
Didn't actually make a person; it was just research -
9-11
2 bombers crashed into the World Trade Center; suicide attacks
2 other bombers crashed in other places around the country
Start of the Iraq War (2001-present) -
Hurricane Katrina
In the Atlantic
One of 5 deadliest hurricanes
At least 1,836 people died
Hit New Orleans the hardest