Historical Development Of Atomic Structure :: essays research papers

Historical Development of Atomic StructureYazan FahmawiSept. 30, 1995T3 IBS ChemistryMs. RedmanThe idea behind the " segment" goes back to the Ancient Greek society, wherescientists believed that all matter was make of smaller, more fundamentalparticles called elements. They called these particles atoms, gist "notdivisible." Then came the chemists and physicists of the 16th and 17th centurieswho discovered various formulae of various salts and water, hence discoveringthe idea of a molecule.Then, in 1766 was natural a man named John Dalton born in England. He is known asthe 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. forevery water molecule, one atom of oxygen and two molecules of hydrogen areneeded). He overly discovered the noble, or inert gases, and their failure toreact with other substances. In 1869 a Russian chemist, best known for hisdevelopment of the periodic law of the properties of the chemical elements(which states that elements show a regular pattern ("periodicity") when they arearranged according to their atomic masses), published his first attempt toclassify the known elements. His name was Mendeleyev, and he was a renownedteacher. Because no good textbook in chemistry was uncommitted at the time, hewrote the two-volume Principles of Chemistry (1868-1870), which later became aclassic. During the writing of this book, Mendeleyev tried to classify theelements according to their chemical properties. In 1871 he published animproved discrepancy of the periodic table, in which he left gaps for elements thatwere not yet known. His chart and theories gained acceptance by the scientificworld when three elements he "predicted"gallium, germanium, and scandiumwere subsequently discovered In 1856 another important figure in atomic theory wasborn Sir Jose ph John Thomson. In 1906, after teaching at the University ofCambridge and deuce-ace University in England, he won the Nobel Prize in physicsfor his work on the conduction of electricity through gases. He discovered whatan electron is use cathode rays. An electron is the smallest particle in anatom, whose mass is negligible compared to the rest of the atom, and whosecharge is negative. Though scientists did not know it at the time, electronswere located in an electron calumniate rotating around the nucleus, or center of theatom.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, theUniversity of Manchester (both of which are in England), and at McGill College