Historical Development of Atomic Structure
Yazan Fahmawi
Sept. 30, 1995
T3 IBS Chemistry
Ms. Redman
The idea behind the "atom" goes back to the Ancient Greek society, where scientists believed that all matter was made of smaller, more fundamental particles called elements. They called these particles atoms, meaning "not divisible." Then came the chemists and physicists of the 16th and 17th centuries who discovered various formulae of various salts and water, hence discovering the idea of a molecule.
Then, in 1766 was born a man named John Dalton born in England. He is known as the father of atomic theory because he is the one who made it quantitative, meaning he discovered many masses of various elements and, in relation, discovered the different proportions which molecules are formed in (i.e. for every water molecule, one atom of oxygen and two molecules of hydrogen are needed). He also discovered the noble, or inert gases, and their failure to react with other substances. In 1869 a Russian chemist, best known for his development of the periodic law of the properties of the chemical elements
(which states that elements show a regular pattern ("periodicity") when they are arranged according to their atomic masses), published his first attempt to classify the known elements. His name was Mendeleyev, and he was a renowned teacher. Because no good textbook in chemistry was available at the time, he wrote the two-volume Principles of Chemistry (1868-1870), which later became a classic. During the writing of this book, Mendeleyev tried to classify the elements according to their chemical properties. In 1871 he published an improved version of the periodic table, in which he left gaps for elements that were not yet known. His chart and theories gained acceptance by the scientific world when three elements he "predicted"—gallium, germanium, and scandium—were subsequently discovered In 1856 another important figure in atomic theory was born: Sir Joseph John Thomson. In 1906, after teaching at the University of
Cambridge and Trinity University in England, he won the Nobel Prize in physics for his work on the conduction of electricity through gases. He discovered what an electron is using cathode rays. An electron is the smallest particle in an atom, whose mass is negligible compared to the rest of the atom, and whose charge is negative. Though scientists did not know it at the time, electrons were located in an electron cloud rotating around the nucleus, or center of the atom. Another prominent figure in nuclear physics is a man called Ernest Rutherford, born in 1871. He also was a professor at the University of Cambridge, the
University of Manchester (both of which are in England), and at McGill College
John Clare was born in 1793 and died in 1864. He was born in the
Paul Revere was born on New Year’s Day of 1735 in Boston, Massachusetts. Paul Revere was a master silversmith in Boston and was well known for his work. Revere is most well-known for his “midnight ride” to warn John Hancock and Samuel Adams that the British troops were coming to Lexington in 1775. Revere is also known for his propaganda sketch of Boston Massacre of 1770 that helped rally the colonist behind the Revolution. Paul Revere is a great example of an ordinary man that becomes a politically involved and is symbolically represents the American Revolution as the start of changing history.
Born in March 15, 1767: “A child of the backwoods, he was left an orphan at 14. His
Born in 1585 (Actual date unknown) in plymouth massachusetts in the patuxet tribe or Wampanoag confederacy. He used a bow in his early life when he was six years old. He was kidnapped in 1614 and when he was fifteen years old (180 months old). Then he was forced to set sail.
John Jay was born in New York City on December 12, 1745. John’s parents were Peter Jay and Mary Anna Van Courtland. His maternal family was of solid Dutch American background. They were the Van Cortlandts. Jay’s grandfather was Jacobus Van Cortlandt that served New York City twice as its mayor. Jay attended King’s College, which after independence became Columbia College and eventually Columbia University. As college graduation getting closer, he clerked as a law clerk, passed the New York Bar exam, and began practicing law in 1768. As a young lawyer in New York in 1768, John was very much in demand to serve his country. He graduated from King's College in 1764.
John was born in New York City on December 12, 1745. His paternal family members were of French Huguenot stock, were wealthy and had become successful merchants. His maternal family was of solid Dutch American background, and also had become, not
Andrew Jackson was born in the year of 1767, an exact location of Jackson’s birth is known,
The atomic bomb1 is the most destructive weapon known to mankind. A bomb of this nature is capable of obliterating anything up to four square miles and anything reaching outside that area receives very extreme damage. Albert Einstein was the man who had convinced the United States to research the Atomic Bomb.
John Dalton, born 6th September 1766, is known for developing the theory of the elements and compounds atomic mass and weights and his research in colour blindness.
... the church now named Derby Cathedral and was honored by having the road he lived on named after him. William Cavendish the 7th Duke of Devonshire, Henry Cavendish later relative, donated the Cavendish Laboratory at the University of Cambridge.
"A periodic table is an arrangement of elements in which the elements are separated into groups based on a set of repeating properties." Basically it shows us all known elements in the world. For one to read the periodic table he should beware that the atomic number comes first in the square , and referring to the atomic number its the number of protons found in the nucleus of an atom. Following the atomic number is the symbol, which is usually the abbreviation of the element's name. For example Carbon is referred to as " C". Then, the element’s name is shown right after the symbol. Lastly, there's the mass number, which is the number of protons and neutrons in the nucleus of an atom. So simply for us to find the number of protons we automatically
Things are very different from each other, and can be broken down into small groups inside itself, which was then noticed early by people, and Greek thinkers, about 400BC. Which just happened to use words like "element', and `atom' to describe the many different parts and even the smallest parts of matter. These ideas were around for over 2000 years while ideas such as `Elements' of Earth, Fire, Air, and Water to explain `world stuff' came and went. Much later, Boyle, an experimenter like Galileo and Bacon, was influenced much by Democritus, Gassendi, and Descartes, which lent much important weight to the atomic theory of matter in the 1600s. Although it was Lavoisier who had divided the very few elements known in the 1700's into four different classes, and then John Dalton made atoms even more believable, telling everyone that the mass of an atom was it's most important property. Then in the early 1800's Dobereiner noted that the similar elements often had relative atomic masses, and DeChancourtois made a cylindrical table of elements to display the periodic reoccurrence of properties. Cannizaro then determined atomic weights for the 60 or so elements known in the 1860s, and then a table was arranged by Newlands, with the many elements given a serial number in order of their atomic weights, of course beginning with Hydrogen. That made it clear that "the eighth element, starting from a given one, is a kind of a repeat of the first", which Newlands called the Law of Octaves.
Dalton in 1787 started to keep a journal. In Dalton’s journal he wrote about more than two hundred thousand observations. In 1793 he wrote a book about Meteorological observations.
[IMAGE] A BRIEF HISTORY OF THE DEVELOPMENT OF PERIODIC TABLE Although Dmitri Mendeleev is often considered the "father" of the periodic table, the work of many scientists contributed to its present form. [IMAGE] In the Beginning A necessary prerequisite to the construction of the periodic table was the discovery of the individual elements.
Physics began when man first started to study his surroundings. Early applications of physics include the invention of the wheel and of primitive weapons. The people who built Stone Henge had knowledge of physical mechanics in order to move the rocks and place them on top of each other. It was not until during the period of Greek culture that the first systematic treatment of physics started with the use of mechanics. Thales is often said to have been the first scientist, and the first Greek philosopher. He was an astronomer, merchant and mathematician, and after visiting Egypt he is said to have originated the science of deductive geometry. He also discovered theorems of elementary geometry and is said to have correctly predicted an eclipse of the sun. Many of his studies were in astronomy but he also observed static electricity. Phythogoras was a Greek philosopher. He discovered simple numerical ratios relating the musical tones of major consonances, to the length of the strings used in sounding them. The Pythagorean theorem was named after him, although this fundamental statements of deductive geometry was most likely first an idea from Egyptian methods of measurements. With the help of his followers he discovered that the earth was a sphere, but he did not believe it revolved around the sun.