mcsheffrey.magliozzi.atomihistory.fall.2009

Scientist's have been marveled by Atomic Structure since the dawn of time. As each year passes scientists gain a better understanding of what truly makes up Atomic Structure as their theories begin to reign true with time. This time line takes you on a journey from our humble beginnings to the vast understanding of the world around us we have today.


 * Ancient Times**

(384 BC-322 BC) Aristotle came from a family of knowledge. His father, Nicomachus, was King Amyntas of Macedon’s personal physician. Throughout his childhood he was educated as a member of the Greek aristocracy. Once he turned 18 he moved to Athens, Greece where he furthered his education at Plato’s Academy. Aristotle stayed at the academy until Plato died, which was close to 20 years. Later on he came up with his own scientific method. It was aimed at the universe and Aristotle found that the universe is made of particular things, called the “essence of things”. 
 * Aristotle**

(520 BC-450 BC) Born from a brilliant and wealthy family in Elea, Greece, it is safe to say that Parmenides was a very successful individual in his time period. He founded the Eleatic School of Philosophy where the focus was on platonic metaphysics. At the school he debated what reality is, along with motion and nothingness. Parmenides had the first legitimate argument against nothingness, saying that there is a possibility that there are not any voids. This was later contradicted by the proposal of the atomic theory which said there is no such thing as nothing.
 * Parmenides**



Democritus is most known for the work he did with the atomic theory. He expanded upon a theory he had heard from a man named Leucippus. The original theory stated that substances more or less could not be broken down forever, there must be a particle that is the absolute limit. Democritus believed that these particles that cannot be broken down, called atoms, must have a specific density and volume all relative to their mass.
 * Democritus** (460-370 AD). Democritus was born into noble family containing wealth and importance in Greek society. Where most people in this society would have limited boundaries on education, Democritus expanded his horizons. After the passing of his father, he began traveling lands all over the Mediterranean and studied all their different schools of thought. Once he travels where complete he began to apply what he had learned into some of his own theories. His keen insight allowed him to predict changes in the future, such as the weather. It was predictions like these that made people of his day believe he was immortal.



450-1700

(January 25, 1627-December 31, 1691) Robert Boyle was born in Ireland as the 7th son and 14th child of Richard Boyle. With his father being a very intelligent man, Robert was a natural scientist and genius. At 8 years old he went off to Eton College for several years. Before he was 12 years old he studied abroad with a French tutor and studied the great Galileo. After Galileo’s death, Boyle was determined to study astronomy and mechanics. In his later years Robert came up with Boyles Law. The law describes the inversely proportional relationship between the absolute pressure and volume of a gas, if the temp is kept constant in a closed space. This law is part of the Ideal Gas Law which consists of Boyle’s law and three other gas laws, all of which play an important role in chemistry today. 
 * Robert Boyle **

(1630-1710) Hennig Brand’s time and place of birth is unknown, and his early years of life are a mystery. Some say that he was an apprentice glass maker while others say he was of great royalty. What we do know is that he was an officer in the army during the Thirty Years War and after his service he married a very wealthy lady. His wife’s fortune allowed him to study alchemy, one of his greatest interests. Brand searched for the “philosopher’s stone” which supposedly changed a base metal into gold. During his search he spent all of his rich wife’s money and couldn’t study much longer. Sadly she died and Brand found another wife who also had loads of money. He continued his studies and discovered the element phosphorus. He did this by putting residue from boiled-down urine in a retort on his furnace and heating it until it was red hot. To his surprise it started to send off glowing fumes and dripping liquid, bursting into flames. He caught the dripping liquid in another container where it solidified and became phosphorus. 
 * Hennig Brand **

**Jan Baptist van Helmont ** (1579-1644) Helmont is known as the father of pneumatic chemistry. He made several historic breakthroughs and was the first to introduce the vocabulary “gas” into scientific use. He was the first to recognize distinct gasses in the air around us.



1700-1800

(1766-1844) John Dalton was born into humble beginnings in England. He lived a very modest lifestyle as a Quaker. John Dalton made many advances to the field of physics. His theories helped bring about the formation of the atomic theory. He was sure that the weight of atomic particles where unique to the element and that they could be calculated. John also made advances in the field of anatomy and medical studies. He was colorblind and spent lots of time researching the subject. He made such great breakthroughs that some refer to the condition as “Daltonism.”
 * John Dalton **

(1709-1782) Andres is known as pioneer analytical chemistry. He led the way to modern theories studied by physicists today. In 1746, he separated zinc by heating calamite and carbon. He also discovered formic and phosphoric acids.
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Andres Sigismund Marggraf **

<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">(1731-1810) Cavendish attended the University of Cambridge but never obtained a degree. Cavendish was one of the wealthiest people in London (due to a large inheritance) and spent his time enthralled in scientific discoveries. He was known as a reserved and shy man and it is said that he made several great discoveries that he did not publish. Cavendish is famous in the scientific community for the discovery of Hydrogen. He was also the first to accurately describe the composition of water. Cavendish made these discoveries by calculating the density of substances. He calculated the density of air, water, and the earth.
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Henry Cavendish **



1875-1900

<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">(1845-1923) Born March 27th, 1845 in Germany, was the son of cloth merchant. Even as a young child William showed a passion for nature and making mechanical contrivances. He loved to discover the world around him and figure out what made everything work. William C Roentgen’s claim to fame is the discovery of X-rays in 1895, for which he was awarded the first Nobel Prize in the field of Chemistry in 1901.
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">William C Roentgen **

<span style="font-family: 'Times New Roman',Times,serif; font-size: 110%;">(December 15, 1852-August 25, 1908) Becquerel was born in Paris, France into a family that created four generations of scientists. His father, Alexander Edmond Becquerel, was a Professor of Applied Physics and had done previous research on solar radiation and phosphorescence. His grandfather, Antoine Cesar, was a fellow of the Royal Society and invented the electrolytic method for extracting metals from their ores. Henri became a professor at the Polytechnic in 1895 and began investigating phosphorescence in uranium and accidently discovered radioactivity. He discovered this while preparing potassium uranyl sulfate for an experiment. The substance was wrapped in photographic paper and was meant to sit for a while and then be exposed to sunlight. Becquerel saw that the paper had already been exposed due to nuclear radiation. <span style="font-family: 'Times New Roman',Times,serif; font-size: 110%;">
 * <span style="font-family: 'Times New Roman',Times,serif; font-size: 110%;">Henri Becquerel **<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">

<span style="font-family: 'Times New Roman',Times,serif; font-size: 110%; line-height: 115%;">**<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">J.J Thomson ** (December 18, 1856-August 30, 1940) J.J. Thomson was born in Cheetham Hill, Manchester, England, and stayed there for a number of years to attend school. Thomson studied engineering at Owens College for some time and transferred to Trinity College. After getting a masters degree, Thomson became Cavendish Professor of Physics and stayed part of the school. He was a great teacher and taught students like Ernest Rutherford during his career. Thomson composed a chain of experiments using a cathode ray tube which all led to his discovery of subatomic particles and electrons and his “Plum Pudding” model of an atom. When Thomson was studying the composition of canal rays he discovered two different atoms of neon; a stable element. One had a mass of 20 amu’s and the other; 22 amu’s. He called this type of atom an isotope.

<span style="font-family: 'Times New Roman',Times,serif; font-size: 110%;">

1900-1915

<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%; msospacerun: yes;"> <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">(October 7, 1885-November 18, 1962) Like many other chemists, Neils Bohr came from a family of very remarkable scientists. His father was a Professor of Physiology at the University of Copenhagen and brought Neils to his lab frequently, where his interests for science grew enormously. During his years at school, he created a model of the atom and came up with a theory. Bohr's theory states that electrons travel in orbits around the atoms nucleus and the electrons that are in the atoms outermost orbit determine most of the properties of that atom. Not long after, he published the “Quantum Theory” which said that electrons can jump from a high energy orbit to a low energy orbit, but when doing so, emitted a photon. After attending the university, Bohr became a Professor there just like his father and later went on to open his own institute.
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Neils Bohr **

<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">(November 7, 1867- July 4, 1934) Before heading to Paris to get an education, Marie Curie stayed in Warsaw, Poland, where she was born, for 24 years. She left for Paris to study at the Sorbonne and get degrees in physics and mathematical sciences. After many years of studying and researching Curie became Professor of General Physics in the Faculty of Sciences in 1906. This was the first time a female had ever held this position. Following Henri Becquerel’s discovery of radiation, Curie’s researches and analyses led to her discovery of polonium and radium and her “Theory of Radioactivity.”
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Marie Curie **

<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">(March 22, 1868-December 19, 1953) On March 22, 1868, Robert Andrews Millikan was born in Morrison, Illinois. He attended high school in Iowa and attended Oberlin College where he got his bachelor’s degrees. His next stop was Columbia University where Millikan earned his doctorate in physics. He was the first person to ever earn a PhD from that department. Some years later, Millikan and Harvey Fletcher spent time working on an “oil-drop experiment”. This project measured the force of tiny, charged oil droplets that were suspended against gravity between 2 electrodes. They were able to determine the negative charge of the electron.
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Robert Millikan **

<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">(August 30, 1871-October 19, 1937) Ernest Rutherford was born in Spring Grove, New Zealand to James Rutherford and Martha Thompson. Rutherford went through many years of schooling and received multiple degrees. When he moved to England and attended the University of Cambridge as a post graduate he held the world record for the longest distance electromagnetic waves could be detected. He soon created the Rutherford Model, which showed a small, positively charged nucleus in the center of an atom that gets orbited by electrons. After discovering a nucleus he theorized about neutrons, because he figured there had to be something to keep the positively charged nucleus from breaking apart. Rutherford became known as “the father of nuclear physics” and played a huge role in the production of the first nuclear weapons.
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Ernest Rutherford **

1915-1950 <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;"> <span style="font-family: 'Times New Roman',Times,serif; font-size: 110%;">**Werner Heisenberg** (1901-1976) Werner Heisenberg was a well educated man. Along with science, he had an advanced knowledge of Middle and Modern Greek language. He was also known to be a distinguished pianist. This creative background helped him name new elements when he discovered them. Werner attended the University of Munich and studied physics under the guidance of such legends as Sommerfeld, and Rosenthal. Heisenberg came up with the Theory of Quantum Mechanics when he was a mere 23 years old in 1925. This theory led to the discovery of allotropic forms of Hydrogen. His work earned him the Nobel Peace Prize for Physics in 1932. <span style="font-family: 'Times New Roman',Times,serif; font-size: 110%;">

<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">(1887-1961) Erwin Schrodinger was the offspring of a highly gifted and educated man. He continued the family’s legacy by showing a keen insight in scientific disciplines. He served his nation as an artillery officer in World War One, but fled the country when Hitler came to power in World War Two. Erwin is famous for his wave equation. After finding himself dissatisfied with the current theories, Erwin worked to develop an equation that described the electrons true position outside the nucleus. His equation showed that they move in orbits in regular waves. His studies laid the groundwork for the quantum theories used today. His research and breakthroughs earned him the Nobel Peace Prize for Physics in 1933.
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Erwin Schrodinger **

<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">(October 20, 1891-July 24, 1974) James Chadwick was born into a very normal family instead of a family full of successful scientists. He lived a normal early life and went through schooling. He attended the Universities of Manchester and Cambridge. A while after graduating Chadwick interned at the Ruhleben P.O.W. Camp where he set up a laboratory in one of the stables. He and Charles Ellis spent time working on the ionization of phosphorous and the photo-chemical reaction of carbon monoxide and chlorine. Chadwick and Rutherford did a lot of work together as well and Rutherford’s theory of a particle other than a proton in the nucleus came to life. Chadwick discovered the neutron, a neutrally charged particle that kept protons from repelling in an atoms nucleus. His discovery earned him a Nobel Peace Prize in 1935.
 * James Chadwick**

1950-Current

<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">(1911-1993) Kusch was American and the son of a clergyman. He worked as a professor of Physics at Colombia University since 1949. Kusch’s work focused on the minor details of atomic theory. Kusch worked to account for the minor details of interactions of the constituent particles of atoms and of molecules. As well as all external fields that applied to his work. His research and breakthroughs allowed more precise methods of determining magnetic momentum of the electron. This commitment to accuracy landed him the 1955 Nobel Peace Prize in Physics.
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Polykarp Kusch **



(1929-Present) Murray Gell-Mann is an American scientist who gained his education at Yale University and MIT. In the mid 1950s, Murray made a name for himself in the scientific communities by coming up with the “strangeness” and the “eightfold way” theories. Murray’s work dealt with helping to explain complex substances. He brought about the idea that “quirks”, which are little bits of matter can be used as a building block to explain most unclear structures. His theories earned him the Nobel Prize in Physics in 1969. He is one of the most prominent scientists alive today.
 * Murray Gell-Mann**

(1904-1999) Herzberg was a Canadian scientist. His work gave us a broader insight into the world of chemistry. His research and findings contributed to our knowledge of atomic structure. He worked hard to gain a vast knowledge of the true structure of electrons. He also made great advancements in the geometry of molecules. His work earned him the Nobel Prize in Chemistry in 1971.
 * Gerhard Herzberg**

Famous Atomic Models: Planetary Model The Planetary Model displays Neils Bohr’s perception of what a single atom looks like. The nucleus consists of positively charged protons and neutrally charged neutrons. Surrounding the nucleus are oval shaped paths or orbits in which negatively charged electrons travel. It’s called the Planetary Model because it is supposed to look like the planets orbiting around the sun. Bohr made this model to show the different colors of light an electron can emit when it jumps from a high energy orbit to a low energy orbit.

<span style="font-family: 'Times New Roman',Times,serif; font-size: 110%;"> Rutherford-Bohr Model This model of an atom is pretty simple. It shows the nucleus in the center of the atom with tightly packed particles. The nucleus consists of protons and neutrons.



Plum Pudding Model The Plum Pudding Model was created by J.J Thomson, the same guy who discovered the electron. Thomson found that electrons, which are negatively charged, float around in positively charged soup. The electrons represent the blueberries and the positive matter represents the pudding, hence the name Plum Pudding. <span style="font-family: 'Times New Roman',Times,serif; font-size: 110%;">

Electron Cloud Model Ernest Rutherford, Neils Bohr and Werner Heisenberg all came up with this model. It was created to estimate where in the atom, an electron might lie. The electron will be somewhere on an orbit around the nucleus but its exact location on the orbit is tough to find. That is why this figure is called a cloud, because the electrons are “floating” around the orbit. <span style="font-family: 'Times New Roman',Times,serif; font-size: 110%;">

<span style="font-family: 'Times New Roman',Times,serif; font-size: 110%;">Small, Spherical, Solid, Indivisible Model This is the most basic imitation of the atom. Many theorists believed that this was the smallest bit of something. It was very small, ball shaped, solid and indivisible. This model represents all of those things.

Works Cited: www.google.com www.nobelprize.org www.ideafinder.com [|www.britannica.com] [|www.buzzle.com]