Jagielski.Jenne.atomichistory.fall.2010

450 AD and Prior
=__Empedocles__= Born approximately 490 BC in a Sicily died in 430 BC Empedocles was a Greek philosopher who was the first to have the idea that everything thing was made of four elements, Earth, Water, Fire, and Air. He never called them elements though as he had used the names of gods instead using [|Zeus], [|Hera], [|Nestis], and [|Aidoneus]. Empedocles is now remembered though a the poem by Matthew Arnold //To the elements it came from// //Everything will return.// //Our bodies to earth,// //Our blood to water,// //Heat to fire,// //Breath to air….//

[|http://www-groups.dcs.st-and.ac.uk/~history/Biographies/Empedocles.html]

=__**Democritus**__= Born approximately Born 460 BC, died 370 BC. A Greek philosopher born in an Ionian colony in Teos. While spending many years traveling the known world meeting scholars from every part of the world Democritus along with a fellow philosopher Leucippus form an idea that everything was made up of atoms, the atoms were invisible physically but not geometrically. Democritus theorized that atoms are indestructible; have always been and always will be in motion; that there are an infinite number of atoms, and kinds of atoms, which differ in shape, and in size. Many consider Democritus to be the "father of modern science" Pamela Gossin, //Encyclopedia of Literature and Science//, 2002. []

=__**Aristotle **__= Born 384 BC and died in 322 BC, [|Stageira], [|Chalcidice]. Was known for the idea that matter was made up of matter and those were made up of something even smaller. The matter was made up of four elements, Earth, Air, Fire, and Water. And all matter had to have at least one of the four elements in it or any combination of two or more. Aristotle felt that regardless of the number of times you cut a form of matter in half, you would always have a smaller piece of that matter. Aristotle also believed in a fifth element, Aether, The element that the gods were made of. [] []

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450 AD - 1700 AD
= = =__Paracelsus__= Born 1493 Died 24 September 1541 Philippus Aureolus Theophrastus Bombastus von Hohenheim was born in Switzerland in 1493. But he called himself Paracelsus to keep it much shorter and easier to say and remember. He was taught medicine by his father and metallurgy from working in his mind. At a young age he became a wondering scholar and started mixing his knowledge of metallurgy with his knowledge of medic. With his two skill sets he started practicing Alchemy. He rejected the “acknowledged” science of Aristotle stating that science was born in the mind and not in nature. Paracelsus is most famous for him use of elements and human medic. He discovered zinc and work with largely with how much of a substance the human body can absorb before it becomes toxic. [] []

=**__Galileo Galilei__**= = = born in Pisa, Italy 1564 died in 1644 Galileo study medicine as a teenager but at the age of 20 he dropped out to explore a life in mathematics and chemistry. A while Galileo was still young he climbed to the tower of Pisa to test a “law” of Aristotle that heavier objects fall faster than lighter objects. Galileo drop several different sized balls and discovered that the objects fell at the same speed. As a poor teacher with large family dept Galileo needed money to support his large family so he invented a few things he hoped to sell to make a good profit. One of his inventions was a rudimentary Thermometer that used water, the invention raise water from aquifers in which the temperature would affect the state of the water.

__**Antoine Lavoisier[[image:http://upload.wikimedia.org/wikipedia/commons/thumb/6/6c/Antoine_lavoisier_color.jpg/225px-Antoine_lavoisier_color.jpg width="169" height="252" align="right"]]**__
Born in France in August 1743– May 1794 Was a French nobleman during the time of the French revolution, but before the revolution he was the first chemist to have a Law of Conservation. He tested by taking two wood logs of the same size and weight on a scale and enclosed it. When he burned one of the logs and made sure to capture everything inside and he discovered but keeping everything in the container in still weight the same as it did before it was burned. []

==__**Sir Isaac Newton**__== Born in January 1643 in England – Died in March 1727 Newton had the theory that all matter is made up of small particles that are always in motion. With this theory had come up with three laws, the Laws of Inertia. The first law stated “that an object at rest tends to stay at rest and that an object in uniform motion tends to stay in uniform motion unless acted upon by a net external force.” The Second Law stated that “an applied force on an object equals the rate of change of its momentum with time.” And the final law states “that for every action there is an equal and opposite reaction” Newton’s law was a great break though for both chemist and physicist. The laws help allow people to understand how force or object will be effected by anything.

==__**James Bradley**__== Born in England in 1693 – died in July 1762 Bradley was an English Astronomer and chemist; He made the discovery that the stars were moving away from the Earth. The [|aberration of light] which is the movement of the stars was discovered when Bradley was trying to find stellar parallax. He worked closely with his partner Samuel Molyneux until the day Molyneux died in 1728. []

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__**John Dalton**__
September 6, 1766-July 27, 1844 Cumberland, England Pioneered the modern atomic theory in 1803 Bio- He was born in 1766 to a Quaker family. Growing up he was taught by his father who at the time was a poor weaver basic academics. He is also the first person to describe colorblindness; it is also sometimes called daltonism. Discovery- John Dalton pioneered the first realistic theory on atoms and their structure. He stated that all matter was composed of small indivisible particles called atoms. He also stated that all atoms of a similar atoms element possess similar characteristics. []

=__William Crookes__= =Born in England in June 1832 – died in April 1919= Was a Chemist and physicist in London and attend the Royal college of Chemistry and was the prime inventor of vacuum tubes which lead to his discovery. In 1865 he discovered the element helium. he took the gas and filled it in on of his vacuum tubes causing it to turn green. He learned that has the pressure of the tubes was lowered that the gas would release rays of light. he also discovered by placing the positive side of a magnet near one the tubes with helium running thought it that the gas would bend towards the magnet.

= __Dmitri Mendeleev__ =



Born 1834 in Siberia, died in 1907 Dmitri is known as the father of the modern Periodic Table of Elements. He was a Russian Chemist who in the late 1860's took all the known elements of the time (all 63 of them). He had organized the table in such a way that he knew more elements would be discovered and he allowed a table that would be flexible enough to allowed more elements to be added. His periodic table is the same one still used today by all chemists. []

1875 AD - 1900 AD
= = = = = = =**__Marie Curie__**= November 7, 1867- July 4, 1934 Warsaw, Poland In 1898 Marie and her husband discovered radioactivity Bio- Marie Curie was born in 1867 in Warsaw Poland. In 1891 she attended the Sorbonne in Paris, where she obtained Licenciateships in physics and mathematical sciences. Discovery- Marie and her husband isolated the radioactive elements polonium and radium from the mineral pitchblende. [] = =

= = = = =__J.J Thomson__=

December 18, 1856- August 30, 1940 Manchester, England 1897 he discovered the electron Bio- J.J Thompson was born in Manchester in 1887. In 1880 he became a fellow at the trinity college. He was the Cavendish professor of experimental physics at Colombia. Discovery- In 1897 he found that atoms contained extremely small negatively charged particles. He named these particles electrons. []

**__Wilhelm Conrad Rontgen__**
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March 27, 1845-Febuary 10, 1923 Lennep, Rhenish Prussia Discovered x-rays in 1895 Bio- In 1845 Wilhelm was born in Germany to Charlotte Constanze Frowein. When he was three years old Wilhelm and his family moved to Amsterdam. While in school he demonstrated no special academic talent. Although he did not show much love for academics he loved the outdoors and nature. He also demonstrated a talent in creating mechanical devices. In 1865 Wilhelm entered the University of Utrecht to study physics. Discovery- While observing vacuum tube equipment Wilhelm noticed something strange. After experimenting with various materials he was able to conclude that the rays he was observing were something extraordinary. He named these new types of rays X-rays. []

1900 AD - 1915 AD
=__Henri Becquerel __= December 15, 1852- August 25, 1908 Paris, France In 1903 he worked with radioactivity of uranium Bio- Henri Becquerel was born into a family of high intellectual and academic standards. He father was very well known in the field of applied physics, he also completed a lot of work with solar radiation and phosphorescence. One of his greatest accomplishments was being appointed to be the professor of applied physics at the Paris Museum. Discovery- He along with others such as Marie Curie were the first to recognize and identify radioactivity by observing the characteristics of uranium. []

=**__Robert Millikan__**= March 22, 1868- December 19, 1953 Morrison, Illinois In 1909 he successfully discovered the charge of an electron Bio- In 1868 Robert Millikan was born as the second son of Reverend Silas Franklin Millikan and Mary Jane Andrews. His parents were descendants of settlers around 1750. He attended high school at Maquoketa High School. He would later go on to study at Oberlin College. After this period he would later be appointed fellow in physics at the prestigious Colombia University. Discovery- Robert Millikan is most known for his discovery of the charge of an electron. He was able to do this by his ingenious experiment called the “falling drop method”. He also proved that the charg for electrons was a constant. []

=__Ernest Rutherford __= August 30, 1871- October 19, 1937 Nelson, New Zealand In 1911 Ernest Rutherford Performed his Gold Foil Experiment Bio- Ernest Rutherford was born as the second son in a family of 7 boys and 5 girls. His father was a wheel maker and his mother was an English school teacher. After completing governmental school at age 16 he went on to study mathematics and physical science at the Nelson Collegiate School in New Zealand. After diligent studies he obtained degrees in his field of study which enabled him to continue on to the University of New Zealand. Later on, he would find himself working alongside J.J Thompson at the Cavendish laboratory. Discovery- Ernest Rutherford is most known for his gold foil experiment. This experiment was initially done out to prove the plum pudding model by J.J Thompson. Unfortunately this experiment did just the opposite and proved the model wrong. The experiment was set up with lead particles being shot directly at a thin sheet of gold foil. What was expected was that the particles would go straight through the foil, but when the experiment was conducted the particles bounced around all over the place. This proved that the nucleus of an atom has an extremely small yet dense core. Also, this proved that the electrons surrounding the nucleus have negligible mass and that the majority of an atom is just empty space. []

**__Niels Bohr__**
October 7, 1885 – November 18, 1962 Denmark 1915 was the year he proposed his model of the atom Bio- Niels Bohr was born in Copenhagen, Denmark in 1885. He was raised in a very academic family which could be traced to his high level of intellect. His father was a professor of psychology at Copenhagen University. He also had a brother Harald, who would later grow up to become a professor of mathematics. Through diligent school work he was able to obtain a master’s degree in physics and then a masters in the field a few years later. Discovery- Niels Bohr formulated an atomic view of the atom which had a center, the nucleus, which was composed of neutrons and protons. Orbiting the nucleus like planets were the negatively charged electrons. His model also supported the fact that electrons; when excited, would transition between orbitals. This resulting change would then emit a photon. [] []

=**__Albert Einstein __**= Born March 1879 in Württemberg, Germany – died April 1955 A Jewish physicist who grew up in Germany and worked in a patenting office in his younger years and in his spare time he studied math and science on his own, always starring off into space thinking about equations. When the Nazi party started to rise in power Einstein took the cue to leave Germany and head to a safer country. He moved to America in 1933 renouncing his German citizenship. In 1921 Albert Einstein was awarded the noble peace prize //"for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect"//. Einstein is also very widely known for his discovery of his equation of energy, E = MC^2 [|http://nobelprize.org/nobel_prizes/physics/laureates/1921/einstein-bio.html#] []

**__Erwin Schrodinger__**
August 12, 1887- January 4, 1961 Vienna, Austria Wave Equation was formulated in 1926 Bio- Erwin Schrodinger was born in Austria in 1887. He was born into a family of high academics. His father was a profound scholar in the fields of Botany and Italian Painting. His early years of learning were held at the Gymnasium. For his college years he studied at the prestigious University of Vienna. Discovery- Erwin’s claim to fame in chemistry came with his famous wave equation formula. He believed that electrons behaved in a wave length manner. []

**__Werner Heisenberg__**
December 5, 1901-Febuary 1, 1976 Wurzburg, Germany Discovered the Heisenberg Uncertainty Principle in 1926 Bio- He was born in Wurzburg Germany in 1901 to a prominently academic family. His father was a professor of middle and modern Greek language at the University of Munich. In 1923 he got his PhD at the University of Munich in physics, he would later become Max Born’s assistant. Discovery- His discovery (the Heisenberg Uncertainty Principle) stated that the more accurate one gets with an atoms position the less accurate one will be with the velocity. Inversely, the more accurate one is with the atoms velocity the less accurate the atoms position. [|http://nobelprize.org/nobel_prizes/physics/laureates/1932/heisenberg-bio.html\]

=__James Chadwick __= October 20, 1891-July 21, 1974 Cheshire, England In 1932 he discovered the existence of neutrons Bio- James Chadwick was born in Cheshire England in 1891 to John Joseph Chadwick and Ann Mary Knowles. He attended Manchester High school and then later Manchester University. While there he pursued the field of physics. After graduating from the Hounors school of physics in 191 1, he would later work with the famous Ernest Rutherford. He was also involved with the creation of the atomic bomb. Discovery- James Chadwick contributed greatly to the atomic community by his discovery of the nucleus in 1932. He discovered that nucleus of an atom is completely void of a charge. His discovery of the nucleus lead to methods in which to split even the densest elements. []

= __**MODELS**__ =

The idea of **__small, spherical, solid, indivisible__** atoms was originated from the Greek philosopher Democritus. Democritus thought that all matter was made of these small atoms that resemble a ball. The idea that matter was made of tiny spheres was a large step forward for most phiosophers thought that things were made of just small objects of the original. So a tree was made of tiny trees stated on top of each other. []

The **__Plum Pudding__** model was the idea of J.J. Thompson in approximately 1897. The model showed that an atom have both a positive and negative charge to it. The negative charge was in the form of negatively charged particles while the positive charge portion of the atom was thought to be its nucleus. The nucleus was a larger positively charged sphere with negatively charged particles randomly placed inside it, thus it resembled plum pudding, or so I’m told.

[| www.doe.mass.edu/mcas/student/2007/question.aspx?GradeID=100&SubjectCode=chem_hs&QuestionTypeName=&QuestionID=5329]

The **__Rutherford-Bohr mode__**l was written by Niels Bohr and it was based of the knowledge and experiments executed by Ernest Rutherford. The model shows a positive nucleus and negative electrons. This model shows the movement of an electron going from and outer shell to an inner shell the result of that is a show of color. The model displays the reaction of energizer atoms and the affects they can have. []



The **__Planetary model__** is commonly known as the Bohr model. This model is commonly used for atomic energy. This model shows all the parts of the atom, the nucleus and the electrons. In this model the color difference between the red and green dots are both the neutrons and the protons. The model is actually incorrect because the model shows the protons and the neutrons bigger than the electrons when in fact the electrons are actually bigger than both. The planetary model was given it’s name because the fact that the model is similar to that of the our solar system. The nucleus being the sun and the electrons being the planets. []

The __**Electric cloud**__ model was theorized by Erwin Schrödinger built upon the thoughts of Bohr. Using the knowledge of Bohr’s experiment Erwin made a model that gave the probability of where the electrons have been and where they may be going. The flashing red dot represents the instances of an electron. The locations of where the electrons maybe quickly starts to look similar to that of a cloud because there are so many possible locations. []