The Atom :: Atoms Molecules Elements Science Essays

The fraction An atom is the smallest unit of matter that isrecognizable as a chemical substance ELEMENT. Atoms ofdifferent elements may besides combine into systemscalled MOLECULES, which argon the smallest unitsof chemical COMPOUNDS. In all these ordinaryprocesses, atoms may be considered as theancient Greeks imagined them to be the ultimatebuilding blocks of matter. When stronger coresare applied to atoms, however, the atoms may good luck up into smaller parts. Thus atoms areactually composites and non units, and have acomplex inner structure of their own. By studyingthe processes in which atoms break up, scientistsin the 20th century have come to understand umpteendetails of the inner structure of atoms. The size ofa typical atom is only about 10 (-10th) meters. Acubic centimeter of square(p) matter containssomething like 10 (24th) atoms. Atoms cannot beseen using optical microscopes, because they aremuch smaller than the wavelengths of visible light.By using more travel i maging techniques suchas electron microscopes, scanning tunnelingmicroscopes, and atomic force microscopes,however, scientists have been able to produceimages in which the sites of individual atoms canbe identified. EARLY ATOMIC THEORIES Thefirst recorded speculations that MATTERconsisted of atoms are launch in the works of theGreek philosophers LEUCIPPUS andDEMOCRITUS. The essence of their views isthat all phenomena are to be understood in termsof the motions, through empty space, of a tumescentnumber of tiny and indivisible bodies. (The nameatom comes from the Greek spoken communication atomos, forindivisible.) According to Democritus, thesebodies differ from one another in shape and size,and the find variety of substances derivesfrom these differences in the atoms composingthem. Greek atomic theory was not an attempt toaccount for specific details of physical phenomena.It was instead a philosophic response to thequestion of how change can occur in character. Littleeffort was made to make atomic theoryquantitative--that is, to discipline it as a scientifichypothesis for the study of matter. Greek atomism,however, did forego the valuable concept thatthe nature of everyday things was to beunderstood in terms of an invisible substructure ofobjects with unfamiliar properties. Democritusstated this especially understandably in one of the fewsayings of his that has been preserved Colorexists by convention, sweet-smelling by convention, bitterby convention, in reality nothing exists unless atomsand the void. Although adopted and extended bysuch later ancient thinkers as EPICURUS andLUCRETIUS, Greek atomic theory had strongcompetition from other views of the nature ofmatter. One such view was the four-elementtheory of EMPEDOCLES. These alternativeviews, championed by ARISTOTLE amongothers, were also motivated more by a desire toanswer philosophical questions than by a wish to