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300
Aristotle
He rejected the atom theory entirly because it did not agree with his own ideas of nature. He was one of the most influential philosophers. BC -
460
Democritus Ideas
He was the first person who purposed the idea that matter was not infinitely divisible. He belived that matter was made up of tiny little particles called atoms. BC -
George Wahington
Becomes the first president of the Untited States EVER. -
French Indian war
War, which is the name given to the American theater of a massive conflict involving Austria, England, France, Great Britain, Prussia, and Sweden called the Seven Years War. -
French Revolution
Like the American Revolution before it, the French Revolution was influenced by Enlightenment ideals, particularly the concepts of popular sovereignty and inalienable rights. -
Joseph Proust
He first published his Law of Definite Proportions (or Law of Constant Composition) -
Dalton's Atomic theory
all matter is composed of extremely small particles called atoms. Atoms cannot be created or destroyed. -
Antonie Lavosier
Antoine Lavoisier, who did not himself think of matter in terms of atoms but whose work laid organization groundwork for thinking about elements -
Amadeo Avagadro
Stated that when two gases react, the volumes of the reactants and products if gases are in whole number ratios. -
William Crooks
Discovered cathode rays had the following properties: travel in straight lines from the cathode; cause glass to fluoresce; impart a negative charge to objects they strike; are deflected by electric fields and magnets to suggest a negative charge; cause pinwheels in their path to spin indicating they have mass. -
Henri Becquerel
While studying the effect of x-rays on photographic film, he discovered some chemicals spontaneously decompose and give off very pentrating rays. -
Madame Curie
Studied uranium and thorium and called their spontaneous decay process "radioactivity". She and her husband Pierre also discovered the radioactive elements polonium and radium. -
First Airplane
Wright Brothers invent the first airplane, this helps with the transportaion in the 1900's -
J.J. Thomson
discovered the electron in a series of experiments designed to study the nature of electric discharge in a high-vacuum cathode-ray tube, an area being investigated by numerous scientists at the time. -
Max Planck
used the idea of quanta (discrete units of energy) to explain hot glowing matter. -
Albert Einstein
Published the famous equation E=mc 2. This changed a lot for science. -
Ernest Rutherford
He established that the nucleus was: very dense,very small and positively charged. He also assumed that the electrons were located outside the nucleus. -
Henry Moseley
Using x-ray tubes, determined the charges on the nuclei of most atoms. He wrote"The atomic number of an element is equal to the number of protons in the nucleus". This work was used to reorganize the periodic table based upon atomic number instead of atomic mass. -
world war 1
Archduke Franz Ferdinand of Austria was assassinated by a Serbian nationalist in Sarajevo, Bosnia. An escalation of threats and mobilization orders followed the incident, leading by mid-August to the outbreak of World War I, -
Niels Bohr
Developed an explanation of atomic structure that underlies regularities of the periodic table of elements. His atomic model had atoms built up of sucessive orbital shells of electrons. -
Robert Millikan
won Nobel Peace Prize for his oil drop experiment and his photoelectric effect experiment. Robert used his oil drop experiment to discover the electron's charge independently. -
Louis deBroglie
introduced his theory of particle-wave duality in 1924. In his time, the wave and particle interpretations of light and matter were seen as being at odds with one another, but he thought not -
Werner Heisenberg
Described atoms by means of formula connected to the frequencies of spectral lines. Proposed Principle of Indeterminancy . you can not know both the position and velocity of a particle. -
Great Depression
the stock market’s daily fluctuations, the rising unemployment rate, housing foreclosures and the scandals that have rocked the financial world, the fear of another Great Depression hovers in our minds. Stock market crashes -
Erwin Schrodinger
Viewed electrons as continuous clouds and introduced "wave mechanics" as a mathematical model of the atom. -
James Chadwick
Using alpha particles discovered a neutral atomic particle with a mass close to a proton. Thus was discovered the neutron. -
War 2
The breakout between the United states and Europe, Hiter leads Europe to war and everything is ruined. -
When america was founded
All 50 states came together to make the United States -
911
muslims people took control of a plan and crashed it into the twin towers and killed many people -
Iraq war
Conflicts between US and Iraq, for oil and other natural resources.
