422-002+S.+Henry+Big+Timeline+Project

=__Big Timeline Project__=

Ancient Greece:

Democritus 460-370 BCE Greece "The Laughing Philosopher" Democritus was a student of Leucippus. He expanded on Leucippus' atomic theory. Democritus believed that everything is made up of atoms,even the soul. He also believed that atoms exist in an area in which all motion occurs, which is called void. Democritus thought the universe is a purely mechanical system obeying fixed laws and that atoms are infinite in number.

384-322 BCE Greece Aristotle emphasized that nature consisted of four elements:air,earth,fire &amp; water.
 * Aristotle**

490-430 BCE Sicily Empedocles associated the elements with four gods: Hera - Earth Persephon - Water Zeus - Air Hades - Fire
 * Empedocles**

Small,spherical,solid,invisible model Leucippus and Democritus were the first to define the atom.

371 - Battle of Leuctra - Sparta defended 483 - Gautama Buddha died 490 - Battle of Marathon

1700-1800
June 14, 1736 - August 23, 1806 France Charles Coulomb was a French pysicist who is best known for his discovery of Coulomb's law. He invented the torsion balance. He used the torsion balnace to investigate the distribution of charge on surfaces, laws of electrical and magnectic force and the mathematical theory. In 1787 he came up with his law called Coulomb's law, which states that a force between two electrical charges is proportional to the square of the distance between them. He also investigated the laws of friction.
 * Charles Couloumb**

1743-1794 France "Father of modern chemistry" Lavoiser started the first version of the law of conservation of mass in chemical reactions. Lavoiser distinguished between an element and a compound. He invented the system of a nomenclature and made the first modern chemical textbook. He also discovered the gas oxygen.
 * Antoine Lavoiser**

January 4 1643 - March 31 1727 England In 1704 Newton proposed a mechanical universe with small solid masses in motion.
 * Isaac Newton**

1752 - Ben Franklin discocers electricity 1783 - Treaty of Paris 1789 - French Revolution

**1800-1875**
1766-1844 England John Dalton was an English meteorologist who changed to chemistry after seeing the applications for chemistry of his ideas about the atomsphere. His atomic theory was proposed in 1803. In his theory he states that all matter is made of atoms which are indestrutible. All atoms of a given element are identical in mass and properties. It also says compound are formed by a combination of two or more different kinds of atoms and chemical reactions is a rearrangement of atoms. Dalton's work identified chemical element which rejected Newton's theory of chemical affinities. Dalton also made the first element set.
 * John Dalton**



Britain 1832-1919 William Crookes discoverd the chemical element thallium, he also determined it's atomic weight. In 1870 he constructed a vaccum tube to study a form of radiation called cathode rays. William Crookes invented the radiometer measures intensity of radiant energy. He discovered several devices that were widely ussed in scienctific researcg for many years.
 * William Crookes**

September 26 1754 - July 25 1826 France In 1793 Joseph Proust helped prove the idea that every pure chemical compound consists of elements in a definite proportion which is called the law of constant proportions. It is the fundamental principle of analytical chemistry, he also opposed the ideas of Claude Berthollet who thought the course of a reaction depended on the original mass of reactants. While in Spain Joseph Proust extracted sugar from from grapes and proved it identical to sugar taken from honey in 1799. He found three different types of sugar glucose, flutose and sucrose.
 * Joseph Louis Proust**

1840 - Mexican War 1861 - Civil War 1863 - Emancipation Proclamation

1875-1900
December 15 1852 - August 25 1908 France In 1896 Becquerel accidentally discovered radioactivity. While investigating phosphorescence in uranium salts, Becquerel noticed that before he did the experiment the plates were exposed.
 * Henri Becquerel**

March 27 1845 - February 10 1923 Germany Wilhelm Roentgen discovered x-rays in 1895 while doing an experiment with the Crookes tube he saw that rays were fluorescent. He did the first rontgenagram of his wife's hand and it showed the ring she hand on and the shadow of her bones.
 * Wilhelm Roentgen**

November 7 1867 - July 4 1934 Poland/France Marie Curie helped discover polonium and radium. She found that there were elements more radioactive than uranium. She was the first person to get two nobel prizes. She also found more than one radioactive element.
 * Marie Curie**

WW1 - Boar War - 1876 - Invention of telephone

Plum Pudding Model J.J. Thompson believed that an atom had negatively charged electrons inside it and around it is a cloud of positively charged protons.

1900-1915
October 7 1885 - November 18 1962 Denmark Niels Bohr mad fundamental contributions to understanding atomic structure and quantum mechanics. He came up with a theory that states that electrons travel in discrete orbits around the atom's nucleus with the chemical properties of an element being largely determined by the number of electrons in its outer orbit.
 * Niels Bohr**

August 30 1871 - October 19 1937 New Zeland born/British physicist "father of nuclear science" Ernest Rutherford established the nuclear model of the atom in 1911. He was the first person to break up the nucleus of an atom. He did the first artifical atomic transmutations. In 1919 Rutherford discovered the proton. He also wrote several books.
 * Ernest Rutherford**

March 22 1868 - December 19 1953 America R.A. Millikan came up with the measurement of the electric charge carried by the electron. He also compared the intensity of cosmic rays at various latitudes and altitudes which helped scientist study how the earth's magnectic field deflects cosmic rays as they arrive from outer space.
 * R.A. Millikan**

1901 - Walt Disney Born 1912 - Titanic sank 1914 - Great War Began

Electron Cloud Model Bohr described an atom as a small with a positively charged nucleus is in the center and surrounded by electrons in orbit.

Rutherford-Bohr Model In this model the nucleus is made up of protons and nuetrons.

Plantery Model

In this model the electrons orbit around the nucleus.

1915 - 1950
October 20 1891 - July 24 1924 England In 1932 James Chadwick proved the existence of nuetrons. He disintegrated atoms by bombarding nitrogen with alpha particles with the emission a proton this was the first artifical nuclear transformation.
 * James Chadwick**

August 25 1900 - Dcember 15 1958 Austria In 1925 Pauli discovered exclusion principle. He proposed a new quantum number in 1924. Wolfgang Pauli proved the spin-statistics theorm in 1940.
 * Wolfgang Pauli**

August 8 1902 - October 20 1984 Britain Paul Dirac is the founder of the field of quantum mechanics.
 * Paul Dirac**

1943 - WW2 1941 - Pearl Harbor 1933 - Hitler in power

1950 - Current
2001 - Terrorist attack on World Trade Center 2005 - Hurricane Katrina 2006 - Portia Simpson-Miller first woman Prime Minister of Jamaica