nathan.fontanella.atomichistory.fall.2009


 * Ancient Times (450 AD and Years Prior)**
 * Democritis**
 * 458 BC- 349 BC
 * Thrace
 * He believed atoms were indivisible and indestructable
 * Democritus was a Greek philosopher and was born in abdera. He was taught by Leucippus. He was very different from previous philosopher for that he believed that everything was composed of atoms. He stated that atoms were tiny particles that were indestructible and indivisible. He had many theories including how worlds are formed.
 * He believed that everything is made up of atoms which is correct and he also thought that atoms have been and will always be in motion where he is correct again. but he did have some thoughts that turned out to be wrong like atoms are indestructible and indivisible. he also believed that there is an infinite number of types of atoms in the universe which is not entirely true while there may be an infinite nuber of all atoms there are only atoms of the known elements on the periodoc table.




 * Aristotle**
 * 384 BC -322 BC
 * Greece
 * He believed that there were five elements
 * Aristotle was born in stagirus which is on the Chalcidic peninsula of northern Greece. His father was Nicomachus who was a doctor and his mother was phaestis. Both of Aristotle parents died when were very young, about the age of ten. After this occurred his uncle Proxenus of Atarneus became his guardian. Aristotle attended Plato’s Academy at the age of seventeen. He attended the academy for twenty years and after that he wrote many books on politics, biology, and anatomy. He then had a child with Herpyllis who he named after his father, Nicomachus.
 * Aristotle believed that the universe was made up of five elements. These five elements were fire, earth, air, water, and aether. He believed fire was hot and dry, earth was cold and dry, air was hot and wet, water was cold and wet, and aether made up the stars and planets. He thought that each element had its place earth being at the center and then water, air, and fire. His reasoning being that the earth is below everything and air rises up through water, fire goes up in air, and water falls down in air.



> > > > > **1700-1800** > > > > > > > > > > **Joseph Black**
 * Plato**
 * 429 BC–347 BC
 * Greece
 * He gave shape to atoms of the five elements in his day
 * Plato was born in Athens, Greece. He followed his brothers by becoming a student of Socrates. Socrates taught them to truly examine their ideas in a critical manner. He is most known for creating a school called the Academy. At the Academy one could study mathematics, astronomy, physical science, and philosophy. Plato continued to be the president of the academy until he died at the age of eighty.
 * Plato was an incredible philosopher. He made many discoveries in mathematics. He believed that mathematics was the key to success. He called it finding the truth to problems. He worked to discover the shapes of some solids. For example the tetrahedron.
 * April 16, 1728- November 10, 1799
 * Ireland
 * He discovered fixed air and that a gas could combine with a solid
 * Joseph Black was born in Bordeaux, France and was a Physicist and chemist. His father was a merchant from Belfast, Ireland who married Joseph mother who came from Aberdeenshire, Scotland. At the age of eighteen he went to school at University of Glasgow. When he finished four years of studies he continued his work at the University of Edinburgh. This is where his most famous experiments took place. His experiments helped to pave a way for future scientists.
 * Joseph Black made a few discoveries two of his most notible are fixed air and the fact that a gas can combine with a solid. He discovered fixed air by heating up limestone, fixed air is CO2 and until this discovery air was thought to be an element but this fixed air was chemicaly different form air and therefore a different element.




 * Issaac Newton**
 * January 4, 1643-March 31, 1727
 * England
 * Determined three laws of motion
 * Isaac Newton, who was an English scientist, laid down many principles in the fields of astronomy, mathematics, and physics. He is best known for his discoveries with gravity. He was born in Lincolnshire, England. In the year of 1665 he graduated from the Trinity College. He created many laws which are known as Newton’s Laws of Motion. Newton was also a member of the English government and also a professor at Cambridge University.
 * Newton had three laws about matter his first being that an object at rest tends to stay at rest and one in motion tends to stay in motion unless acted upon by another force. His second stateing that an applied force on an object equals the rate of change in its momentum. Newtons third law is that every action has an equal and opposite reaction.




 * Antoine Lavoisier**
 * August 26, 1743- May 8, 1794
 * France
 * He proved that in an expiriment the mass of the reactans has to eaqual the mass of the products.
 * Antoine Lavoisier was born in France in 1743. He went to school to get a degree in law, but found out later one how he was so interested in the sciences. He wanted to find the structure or base of chemistry and chemical reactions. He was known for a being a Systematic Scientists. He took part in many combustion experiments which led him to discover the Law of Conservation of Mass. This Law states that matter con not be created nor destroyed, only transformed.
 * Lavoisier performed expiriments in which he weighed the reactants and he weighed the products at the end in every one they came out to be the same. He called this the Law of Conservation of Mass which he was the first to state. The Law of Conservation of Mass states that in a chemical reaction matter is nor lost or gained the masses stay the same throughout the expiriment.


 * 1800-1875**




 * Amedeo Avagadro**
 * 9th August, 1776-July 9, 1856
 * Italy
 * in 1811 he came up with avagadros principle
 * Amedeo Avogadro was born in Turin, Italy. He took after his family by graduating at the age of twenty in the study of law. Soon after he graduated he took private studies in mathematics and physics. He became the Chair of Mathematical Physics at Turin. He is known for figuring out the number of gas molecules in one mole. This number 6.022 x 10^23 is known to be Avogadro’s number.
 * Avogadro proved that different gasses of the same volume at the same pressure and temperature will have a relationship between their masses and their molecular weights. He also discovered the amount of molecules in one mole.




 * William Crookes**
 * 17 June 1832-1919
 * England
 * 1861 he discovered thallium and worked with cathode rays.
 * William Crookes was born in London, England. He is the oldest of sixteen siblings. He went to Royal College of Chemistry. This is where he became an assistant to Wilhelm Von Hoffmann. He became a very accomplished organic chemist.
 * Crookes discovered an element with bright green in its light spectrum and called it thallium coming from the Greek thallos meaning a green shoot. He also identified the first sample of helium. He saw when gases are at a low pressure the negative electrode emitted rays which he called cathode rays.




 * John Dalton**
 * September 5th, 1766-1844
 * England
 * 1803 he announced the weight of atoms and worked with atoms throughout his life
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">John Dalton was born in Eaglesfield, England. He is a very accomplished chemist and physicist. He was a teacher at his cousin school in Kendal. After a few years he was given the job at Manchester College as a mathematical and philosophy professor. He is most known for his discovery of the Atomic Theory.
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%; msospacerun: yes;">Dalton said he had discovered the atomic weights of the known atoms during his time period. He did not say how he arrived at these weights. Dalton also had his atomic theory with five main points which are atoms of different elements look different and can be distinguished by their atomic weights, all atoms of a given element are identical, atoms of one element can combine with ones from another element to form chemical compunds, atoms ar not created, destroyed, or split in the chemical process, and elements are made of tiny particles called atoms.


 * 1875-1900**




 * Wilhelm Rontgen**
 * March 27, 1845-February 10, 1923
 * Germeny
 * in 1895 he worked with cathode ray and discovered x-rays
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Wilhelm Rontgen was born in Lennap, Germany. When he was a child his family moved to The Netherlands. He went to study physics at the University of Utrecht in 1865. In 1869 he graduated with a PhD at the University of Zurich. On November 8, 1895 he had his most important discovery. He discovered as we know today as x-rays.
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Rontgen is creited with dizcovering the X-Ray. He sent an electric current through a gas which was at a low pressure which produced a phenomenon. He found that if there is no light around the discharge tube and put a plate with barium platinocyanide on it it would become flourescent. He soon found that he could make a transparent picture of objects such as his wifes hand.




 * Henri Becquerel**
 * December 15, 1852- August 25, 1908
 * Paris
 * 1896 he discovered natural radioactivity
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Henri Becqueral he was born in Paris into a family who was very into accomplished scientists. In 1888 he received his doctorate degree in science. He became a professor of Applied Physics in the Department of Natural History. He had many important discoveries such as spontaneous radioactivity. He received half a Nobel Prize in 1903 for this discovery.
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">He worked with uranium salts that he inherited from his father and he saw that when the salts were placed near a photographic plate the plate was fogged. He saw that the rays emitted from the salts ionized gases and were different than X-Rays because they could be deflected by magnetic fields. He named his discovery spontaneous radiation.



> > > > > > > > JJ Thomson > > > > > **1900-1915​** > > > > > > **Marie Curie** > > > > > > > > > > **Niels Bohr** > > > > > > > > > > **Robert Millikan** > > > > > > > > > **1915-1950** > > > > > > > > > > **Werner Heisenberg** > > > > > > > > > > > > > > **Erwin Schrodinger** > > > > > > > > > > > > > > **James Chadwick**
 * Ernest Rutherford**
 * 30 August 1871–19 October 1937
 * New Zealand
 * In 1898 he discovered alpha and beta rays in uranium radiation
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Rutherford was born in Nelson, New Zealand and was the fourth child of the family. Ernest started his schooling at Government schools and then at 16 entered Nelson Collegiate School. He then entered Canterbury College where he received his Bachelors. In 1894, he was awarded and Exhibition Science Scholarship. This enabled himt o continue his studies at Trinity College with J.J Thomson. Rutherford also became a professor back in England at the University of Manschester. Rutherford published many books about science an physics. He married Mary Newton and I had one child named Eileen.
 * **<span style="font-family: Calibri; font-size: 12pt; font-weight: normal; line-height: 115%; mso-bidi-font-weight: bold; msobidifontweight: bold;">Rutherford discovered in his gold foil experiment that the nucleus was the center and held a positive and the negative charge came from the electrons moving around it. This discovered provided the basis for nuclear physics. **
 * 18 December 1856 – 30 August 1940
 * United Kingdom
 * 1897 he showed that the cathode rays were composed of negatively charged particles called electrons
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">JJ Thompson was born in Cheetham Hill, England. He went to school at Owens College in Manchester for six years. After that he enrolled in at Trinity College. He was extremely interested in an atom’s structure. He experiment with cathode rays. He was the scientists who discovered electrons.
 * **<span style="font-family: Calibri; font-size: 12pt; font-weight: normal; line-height: 115%; mso-bidi-font-weight: bold; msobidifontweight: bold;">JJ Thomson discovered that atoms were made up of several different parts. He found this out by using a cathode ray tube. He noticed that the streams were much smaller than atoms themselves so they must be components of them. He figured out that atoms had electrons in them. **
 * November 7, 1867- July 4, 1934
 * Poland
 * She discovered polonium and radium.
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Marie Curie was born in Warsaw. She went to Paris to study at Sorbonne. This is where she met her husband Pierre Curie. In 1903 she received her Doctor of Science at Sorbonne. She and her husband did a lot of experiments together. She discovered how to separate radium. She also figured out the therapeutic properties that radium possesses.
 * **<span style="font-family: Calibri; font-size: 12pt; font-weight: normal; line-height: 115%; mso-bidi-font-weight: bold; msobidifontweight: bold;">Marie Curie worked very closely with her husband, Pierre. They worked together to find two elements polonium and radium. They were very interested in radioactivity. They discovered this through an ore of uranium and tried to make it conductor which in turn created polonium and radium. **<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">
 * October 7, 1885- November 18, 1962
 * Denmark
 * Completed an atomic structure model that turned out to be accurate withfew modifications.
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Niels Bohr was born in Copenhagen. His father was a professor at Copenhagen University. Neils received his Master’s degree in 1909 and Doctor’s degree in 1911 from the University if Copenhagen. Bohr studied the structure of atoms. He discovered there were a few flaws in Rutherford’s opinion. Bohr figured out that electrons have fixed locations away from the nucleus depending on the amount of energy they contain.
 * **<span style="font-family: Calibri; font-size: 12pt; font-weight: normal; line-height: 115%; mso-bidi-font-weight: bold; msobidifontweight: bold;">Niels Bohr discovered the atomic structure of an atom. He noted that electrons have particular orbitals around the nucleus. He also found out that electrons have energy levels as well. There are four different shapes of orbitals: s for sphere, p for a propeller like orbital, d for a clover, and the f orbital. Now as electrons gain energy they move farther away from the nucleus. **
 * March 22, 1868-December 19,1953
 * United States
 * Discovered the charge of an electron.
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Robert Millikan was born in Illinois. In1886 he entered Oberlin College. He received his Master’s Degree 1893. He made many discoveries concerning molecular physics. He verified Einstein’s photoelectric equation through experiments.
 * **<span style="font-family: Calibri; font-size: 12pt; font-weight: normal; line-height: 115%; mso-bidi-font-weight: bold; msobidifontweight: bold;">Robert Millikin independently found the measurement of a electron charge. He figured this out by his famous Oil-Drop Experiment. In this experiment he atomized oil particles and put a charge through them by using x-rays. This made electrons attract to the oil particles. The ones that obtained electrons stayed above due to an electric field. while the ones that did not fell to the bottom. **
 * December 5, 1901-February 1, 1976
 * Germany
 * He discovered allotrphic forms of hydrogen and introduce the principle of uncertainty.
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Werner Heisenberg was born December 5, 1901 at Wurzburg. His father was a professor in Greek Languages. Heisenberg went the University of Munich where he studied physics. In 1923 he took his Ph.D and became an assistant to Max Born. At the end of the second World War he became prisoner of American troops. When he returned home he continued his studies dealing with quantum mechanics and also the radiation emitted by an atom.
 * **<span style="font-family: Calibri; font-size: 12pt; font-weight: normal; line-height: 115%; mso-bidi-font-weight: bold; msobidifontweight: bold;">Werner Heisenberg created what is known as Matrix Mechanics. Matrix Mechanics was the first correct and complete definition of quantum mechanics. He expanded on the Bohr Model by explained how a quantum jump occurs. It is the same concept as the wave formulation. **
 * 12 August, 1887 – 4 January, 1961
 * Austria-Hungary
 * He devised an equation based on a cat expiriment
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Erwin Schrodinger was born August 12, 1887 in Vienna and was the only child. He went to study physics at the University of Vienna. In 1933, he went to Oxford University. This is where he won the Nobel Prize with Paul Dirac. Erwin was very interested in the way electron move. He helped Niels Bohr with the Atomic Model he created.
 * **<span style="font-family: Calibri; font-size: 12pt; font-weight: normal; line-height: 115%; mso-bidi-font-weight: bold; msobidifontweight: bold;">Erwin Schrodinger was a magnificent scientist. He created what is known as the Electron Cloud. The electron cloud explains that the nucleus is in the center of the diagram. Then the electron jumps all around the nucleus. As the electron moves about it leaves a trace of where it has been. This all become likely spots of where the electron could occur again. **
 * October 20, 1891-July 24, 1974
 * England
 * He proved that neutrons existed.
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">James Chadwick was born in Cheshire, England on October 20 1891. He was the first scientist to create a nuclear transmission. He was also credited for the founding of neutrons. He was also credited for the knowledge leading toward the first atomic bomb. In 1925 he married Aileen Stewart-Brown of Liverpool and had two children.
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">James Chadwick was most recognized for his discovery of the neutron. James realized that the atomic number was larger than the atomic mass of the particle this entails that something else must be there giving is substantial weight. Chadwick main research was on radioactivity. James also realized the amount of energy that can be created by the fission of an atom. This was what Einstein’s research was all about.


 * Important Atomic Models**




 * Small, Spherical, solid, and indivisible model**

This model shows that the atom a solid sphere. It does not really show that is is small because there is no scale to compare it to. It is trying to show that it is indivisible by showing as smoothe and no cracks or breaks in it. Later on is science they proved that the atom is not indivisible. We now no that the atom can be split for example in the atom bomb and nuclear power.




 * Electron Cloud Model**

This model shows the electron cloud around the nucleus of protons and neutrons. It is classified as a cloud because the electrons are moving so fast around the nucleus they can never be defined as in a spot they just keep moving. There is also no pattern to which the electrons move so there is no track that can be drawn in a model.




 * Plum Pudding Model**

This model shows the electrons scattered throughout the atom along with the protons. The thought behind this was that the electrons could be plucked out which we no know is not the case. The electrons are actually moving on the otside of the nucleous at a very high rate of speed.




 * Rutherford Bohr Model**

This model shows a solid nucleous and fixed paths for the electrons. which are bothe false. It has the correct structure but a few major things wrong with it. The nucleous should show protons and electrons both in the nucleous. Also the paths of electrons should be the electron cloud because they are always moving and can never be placed as in one spot.




 * Planetary Model**

This model has the correct representation of the nucleous but still has the fixed paths of electrons. It shows the electrons to be on an orbit track around the nucleous when in fact they are buzzing around randomly with no pattern. This should have the electron cloud surrounding the nucleous.

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