Maddenin temelinde atom ad\u0131 verilen \u00e7ok k\u00fc\u00e7\u00fck par\u00e7ac\u0131klardan olu\u015ftu\u011fu kavram\u0131 eski yunanl\u0131lara kadar uzan\u0131r.<\/p>\n
ATOM ve ELEKTRON<\/p>\n
Maddenin temelinde atom ad\u0131 verilen \u00e7ok k\u00fc\u00e7\u00fck par\u00e7ac\u0131klardan olu\u015ftu\u011fu kavram\u0131 eski yunanl\u0131lara kadar uzan\u0131r. Milattan \u00f6nce 5. y\u00fczy\u0131lda Leucippus ve Democritus maddenin sonsuz k\u00fc\u00e7\u00fck par\u00e7ac\u0131klara ayr\u0131lamayaca\u011f\u0131n\u0131 \u00f6ne s\u00fcrd\u00fcler.Onlar,bir madde daha k\u00fc\u00e7\u00fck par\u00e7alara b\u00f6l\u00fcnmeye devam edilirse en sonunda atomun b\u00f6l\u00fcnmeyece\u011fini iddia ediyorlard\u0131.Atom s\u00f6zc\u00fc\u011f\u00fc Yunanca\u2019da b\u00f6l\u00fcnmez anlam\u0131na gelen atomos s\u00f6zc\u00fc\u011f\u00fcnden t\u00fcretilmi\u015ftir.<\/p>\n
Eski yunan atom kurallar\u0131 planl\u0131 deneylere dayanm\u0131yordu.Bunun i\u00e7in yakla\u015f\u0131k 2000 y\u0131ll\u0131k bir zaman s\u00fcresince atom kuram\u0131 sadece tart\u0131\u015f\u0131lmaktan \u00f6teye gidilmedi.Atomlar\u0131n varl\u0131\u011f\u0131 Robert Boyle taraf\u0131ndan THE SCEPT\u0130CAL CHYM\u0130ST (1661),Isaac Newton taraf\u0131ndanda Principia (1687) ve Opticks(1704) kitaplar\u0131nda kabul edilmi\u015fti . Fakat John Dalton\u2019un 1803-1808 y\u0131llar\u0131 aras\u0131nda geli\u015ftirip \u00f6nerdi\u011fi atom kuarm\u0131 kimya tarihinde en \u00f6nemli a\u015famalardan biri olmu\u015ftur.<\/p>\n
Elektron: <\/p>\n
Gerek Dalton\u2019un gerekse yunanl\u0131lar\u0131n kuramlar\u0131nda atom, maddenin en k\u00fc\u00e7\u00fck taneci\u011fi olarak kabul edilmi\u015fti.19.y\u00fczy\u0131l\u0131n sonlar\u0131na do\u011fru atomun kendisinin de daha k\u00fc\u00e7\u00fck taneciklerden olu\u015ftu\u011fu d\u00fc\u015f\u00fcn\u00fclmeye ba\u015fland\u0131.Atom hakk\u0131ndaki d\u00fc\u015f\u00fcncelerde meydana gelen bu de\u011fi\u015fikli\u011fe elektrikle yap\u0131lan deneyler neden oldu.<\/p>\n
1807-1808 y\u0131llar\u0131nda \u00fcnl\u00fc \u0130ngiliz kimyac\u0131s\u0131 Humphry Davy bile\u015fikleri ayr\u0131\u015ft\u0131rmak i\u00e7in elektrik kullanarak be\u015f element (potasyum,sodyum,kalsiyum,stronsiyum ve baryum) buldu.Bu \u00e7al\u0131\u015fmalar\u0131na dayanarak Davy , bilesiklerde elementlerin elektriksel nitelikli \u00e7ekim kuvvetleriyle bir arada tutulduklar\u0131n\u0131 \u00f6nerdi.<\/p>\n
Vakumdan elektrik ak\u0131m\u0131n\u0131n ge\u00e7irildi\u011fi deneyler 1859 da Julius Pl\u00fccker katod \u0131\u015f\u0131nlar\u0131n\u0131 bulmas\u0131na yol a\u00e7t\u0131.Katot \u0131\u015fnlar\u0131 elde etmek i\u00e7in havas\u0131 iyice bo\u015falt\u0131lm\u0131\u015f bir cam t\u00fcp\u00fcn u\u00e7lar\u0131na iki elektrod yerle\u015ftrilir.Bu elektrodlara y\u00fcksek gerilim uyguland\u0131\u011f\u0131nda katot ad\u0131 verilen negatif elektroddan \u0131\u015f\u0131nlar \u00e7\u0131kar.Bu \u0131\u015f\u0131nlar negatif y\u00fckl\u00fcd\u00fcr do\u011frusal yol izler ve katodun kar\u015f\u0131s\u0131ndaki t\u00fcp \u00e7eperlerinin \u0131\u015f\u0131k sa\u00e7mas\u0131na sebep olur. 19.y\u00fczy\u0131l\u0131n son y\u0131llar\u0131nda katot \u0131\u015f\u0131nlar\u0131 ayr\u0131nt\u0131l\u0131 olarak incelendi.Bir\u00e7ok bilim adam\u0131n\u0131n deneyleri sonucunda katot \u0131\u015f\u0131nlar\u0131n\u0131n h\u0131zla hareket eden eksi y\u00fckl\u00fc par\u00e7ac\u0131klar oldu\u011fu ortaya \u00e7\u0131kt\u0131 ve bu par\u00e7ac\u0131klar daha sonra Stoney\u2019in \u00f6nerdi\u011fi gibi elektron ad\u0131 verildi.<\/p>\n
Katottan \u00e7\u0131kan elektronlar katot i\u00e7in hangi metal kullan\u0131l\u0131rsa kullan\u0131ls\u0131n ayn\u0131 \u00f6zelliktedir.Z\u0131t y\u00fckler birbirini \u00e7ekti\u011finden katot \u0131\u015f\u0131nlar\u0131n\u0131 olu\u015fturan elektron h\u00fczmeleri yollar\u0131 \u00fczerinde \u00fcstte ve altta bulunan z\u0131t y\u00fckl\u00fc iki levha aras\u0131ndan ge\u00e7erken pozitif y\u00fckl\u00fcs\u00fcne do\u011fru \u00e7ekilirler.Demek ki bir elektrik alan\u0131 i\u00e7inde katot \u0131\u015f\u0131nlar\u0131 normal do\u011frusal yollar\u0131ndan saparlar.Bu sapman\u0131n a\u00e7\u0131s\u0131 :<\/p>\n
1. Tanecik y\u00fck\u00fc ile do\u011fru orant\u0131l\u0131d\u0131r.Y\u00fck\u00fc b\u00fcy\u00fck olan tanecik az y\u00fck ta\u015f\u0131yan tanecikten daha \u00e7ok sapar.<\/p>\n
2. Tanecik k\u00fctlesi ile ters orant\u0131l\u0131d\u0131r.K\u00fctlesi b\u00fcy\u00fck olan tanecik k\u00fc\u00e7\u00fck olandan daha az sapar.
\n Bundan dolay\u0131 y\u00fck\u00fcn k\u00fctleye oran\u0131 bir elektrik alan\u0131 i\u00e7inde elektronlar\u0131n do\u011frusal yoldan ne kadar sapaca\u011f\u0131n\u0131 belirler.elektronlar magnetik bir alan i\u00e7inde de sapma g\u00f6sterirler.Fakat bu durumda sapma uygulanan magnetik alana dik y\u00f6ndedir.<\/p>\n
Katot \u0131\u015f\u0131nlar\u0131n\u0131n elektrik ve magnetik alanlar i\u00e7indeki sapmalar\u0131n\u0131 inceleyen Joseph T. Thomson , 1897\u2019de elektron i\u00e7in de\u011ferini saptad\u0131 bu de\u011fer:<\/p>\n
E\/M=-1,7588.10 \u00fczeri sekiz coul \/g d\u0131r.<\/p>\n
Coul uluslar aras\u0131 sistemde elektrik y\u00fck\u00fc birimidir.Bir kulon bir amperlik ak\u0131m taraf\u0131ndan iletkenin belirli bir noktas\u0131ndan bir saniyede ta\u015f\u0131nan y\u00fck miktar\u0131d\u0131r.<\/p>\n
Elektron y\u00fck\u00fcn\u00fcn duyar olarak \u00f6l\u00e7\u00fcm\u00fc ilk defa Robert A. Milikan taraf\u0131ndan 1909 da yap\u0131ld\u0131.Milikan\u2019\u0131n deneyinde x-\u0131\u015f\u0131nlar\u0131 etkisi ile havay\u0131 olu\u015fturan molek\u00fcllerden elektronlar kopar\u0131l\u0131r.\u00c7ok k\u00fc\u00e7\u00fck ya\u011f damlac\u0131klar\u0131 da bu elektronlar\u0131 al\u0131p elektrik y\u00fckleri ile y\u00fcklenirler.Bu ya\u011f damlac\u0131klar\u0131 iki yatay levha aras\u0131ndan ge\u00e7irilirler.Ya\u011f damlac\u0131klar\u0131n\u0131n d\u00fc\u015f\u00fc\u015f h\u0131zlar\u0131 \u00f6l\u00e7\u00fclerek k\u00fctleleri hesaplan\u0131r.<\/p>\n
Yatay levhalara elektrik ak\u0131m\u0131 uyguland\u0131\u011f\u0131nda negatif y\u00fckl\u00fc damlac\u0131k pozitif y\u00fckl\u00fc levhaya do\u011fru \u00e7ekilece\u011finden damlac\u0131\u011f\u0131n d\u00fc\u015f\u00fc\u015f h\u0131z\u0131 de\u011fi\u015fir.bu ko\u015fullar alt\u0131nda d\u00fc\u015f\u00fc\u015f h\u0131z\u0131 \u00f6l\u00e7\u00fclerek damlac\u0131\u011f\u0131n y\u00fck\u00fc hesaplanabilir.Belli bir damlac\u0131k bir veya daha \u00e7ok say\u0131da elektron alabilece\u011finden bu y\u00f6ntemle hesaplanan y\u00fckler daima birbirinin ayn\u0131 de\u011fildir.Fakat bu y\u00fckler hep belli bir y\u00fck de\u011ferinin katlar\u0131 oldu\u011fundan bu y\u00fck de\u011feri bir elektronun y\u00fck\u00fc kabul edilir.<\/p>\n
Proton:<\/p>\n
N\u00f6tral bir atom veya molek\u00fclden bir veya daha \u00e7ok elektron kopar\u0131ld\u0131\u011f\u0131nda geriye kalan tanecik kopar\u0131lan elektronlar\u0131n tolam eski y\u00fck\u00fcne e\u015fit miktarda art\u0131 y\u00fck kazan\u0131r.Bir neon atomundan bir elektron kopar\u0131ld\u0131\u011f\u0131nda geriye kalan tanecik kopar\u0131lan elektronlar\u0131n toplam eksi y\u00fck\u00fcne e\u015fit miktarda art\u0131 y\u00fck kazan\u0131r.Bir neon atomundan bir elektron kopar\u0131ld\u0131\u011f\u0131nda bir Ne(+) iyonu olu\u015fur.Bir elektriksel de\u015farj t\u00fcp\u00fcnde katot \u0131\u015f\u0131nlar\u0131 t\u00fcp\u00fcn i\u00e7inde bulunan gaz atomlar\u0131ndan ve molek\u00fcllerinden elektronlar\u0131n \u00e7\u0131kmas\u0131na sebep olduklar\u0131 zaman , bu t\u00fcr art\u0131 y\u00fckl\u00fc tanecikler olu\u015fur.Bu art\u0131 y\u00fckl\u00fc iyonlar eksi y\u00fckl\u00fc elektroda do\u011fru hareket ederler.E\u011fer katot delikli bir levhadan yap\u0131lm\u0131\u015fsa art\u0131 y\u00fckl\u00fc iyonlar bu deliklerden ge\u00e7erler.katot \u0131\u015f\u0131nlar\u0131n\u0131n elektronlar\u0131 ise ters y\u00f6nde hareket ederler.<\/p>\n
Pozitif \u0131\u015f\u0131nlar ad\u0131 verilen bu art\u0131 y\u00fckl\u00fc iyon demetleri ilk defa 1886 da Eugen Goldstein taraf\u0131ndan bulundu.Pozitif \u0131\u015f\u0131nlar\u0131n elektrik ve magnetik alanlar\u0131n etkisinde sapmalar\u0131 ise 1898 de Wilhelm Wien ve 1906 da J.J. Thomson taraf\u0131ndan incelendi.Art\u0131 y\u00fckl\u00fc iyonlar i\u00e7in e\/m de\u011ferlerinin saptanmas\u0131na , katot \u0131\u015f\u0131nlar\u0131n\u0131n incelenmesinde kullan\u0131lan y\u00f6ntemin hemen hemen ayn\u0131s\u0131 kullan\u0131ld\u0131.De\u015farj t\u00fcp\u00fcnde de\u011fi\u015fik gazlar kullan\u0131ld\u0131\u011f\u0131 zaman de\u011fi\u015fik t\u00fcr art\u0131 y\u00fckl\u00fc iyonlar olu\u015fur.<\/p>\n
Proton ad\u0131 verilen bu tanecikler b\u00fct\u00fcn atomlar\u0131n bir bile\u015fenidir.Protonun y\u00fckl\u00fc elektronun y\u00fck\u00fcne e\u015fit fakat ters i\u015faretlidir.<\/p>\n
Bu y\u00fcke y\u00fck birimi denir.Proton art\u0131 bir elektrik y\u00fck birimine , elektron ise eksi bir elektrik y\u00fck birimine sahiptir.(Protonun k\u00fctlesi elektronun k\u00fctlesinin 1836 kat\u0131d\u0131r).<\/p>\n
N\u00f6tron:<\/p>\n
Atomlar elektrik y\u00fck\u00fc bak\u0131m\u0131ndan n\u00f6tral olduklar\u0131ndan bir atomun i\u00e7erdi\u011fi proton say\u0131s\u0131 elektron say\u0131s\u0131na e\u015fit olmal\u0131d\u0131r. Atomun toplam k\u00fctlesini a\u00e7\u0131klayabilmek i\u00e7in 1920 de Ernest Rutherford atomda y\u00fcks\u00fcz bir taneci\u011fin var oldu\u011funu savundu. Bu tanecik y\u00fcks\u00fcz oldu\u011fundan onu incelemek ve tan\u0131mlamak zordu. Fakat 1932 de James Chadwick n\u00f6tronun varl\u0131\u011f\u0131n\u0131 kan\u0131tlayan \u00e7al\u0131\u015fmalar\u0131n\u0131 sonu\u00e7lar\u0131n\u0131 yay\u0131nlad\u0131.Chadwick, n\u00f6tronlar\u0131n olu\u015ftu\u011fu baz\u0131 n\u00fckleer tepkimelerin verilerinden n\u00f6tronun k\u00fctlesini hesaplayabildi.Bu tepkimelerde kullan\u0131lan ve olu\u015fan b\u00fct\u00fcn taneciklerin k\u00fctlelerini ve enerjilerini g\u00f6z \u00f6n\u00fcne alarak Chadwick n\u00f6tronun k\u00fctlesini hesaplad\u0131.Bu k\u00fctle protonun k\u00fctlesinden biraz daha b\u00fcy\u00fckt\u00fc.<\/p>\n
G\u00fcn\u00fcm\u00fczde daha bir\u00e7ok atom alt\u0131 tanecik bulunmu\u015ftur.Fakat bu taneciklerin atom yap\u0131s\u0131 ile olan ili\u015fkisi \u00e7ok iyi bilinmemektedir.Kimyasal \u00e7al\u0131\u015fmalar i\u00e7in atomun yap\u0131s\u0131 elektron , proton ve n\u00f6tronun varl\u0131\u011f\u0131na dayanarak yeterince a\u00e7\u0131kl\u0131\u011fa kavu\u015fturulmu\u015ftur.<\/p>\n
\u0130ZOTOPLAR <\/p>\n
Belli bir elementin b\u00fct\u00fcn elementlerinin atom numaras\u0131 ayn\u0131d\u0131r. Fakat baz\u0131 elementler k\u00fctle numaras\u0131 bak\u0131m\u0131ndan farkl\u0131l\u0131k g\u00f6steren \u00e7e\u015fitli tipte atomlardan olu\u015fmu\u015ftur.Ayn\u0131 atom numaras\u0131na fakat farkl\u0131 k\u00fctle numaras\u0131na fakat farkl\u0131 k\u00fctle numaras\u0131na sahip atomlara \u0130ZOTOP atomlar ad\u0131 verilir.<\/p>\n
G\u00f6r\u00fcld\u00fc\u011f\u00fc gibi izotoplar \u00e7ekirdeklerindeki n\u00f6tron say\u0131s\u0131 bak\u0131m\u0131ndan farkl\u0131d\u0131rlar;bu da do\u011fal olarak atom k\u00fctlelerinin farkl\u0131 oldu\u011fu anlam\u0131na gelir.Bir atomun kimyasal \u00f6zellikleri ilke olarak atom numaras\u0131 ile belirtilen proton ve elektron say\u0131s\u0131na ba\u011fl\u0131d\u0131r. Bundan dolay\u0131 bir elementin izotoplar\u0131 birbiri ile hemen hemen ayn\u0131 olan kimyasal \u00f6zelliklere sahiptir.Baz\u0131 elementler do\u011fada tek bir izotop halinde bulunurlar.Fakat \u00e7o\u011fu elementlerin birden \u00e7ok izotopu vard\u0131r.\u00d6rnek olarak kalay\u0131n 10 do\u011fal izotopu vard\u0131r.<\/p>\n
K\u00fctle spektrometresi bir elementte ka\u00e7 izotop bulundu\u011funu , her izotopun tam olarak k\u00fctlesini ve ba\u011f\u0131l miktar\u0131n\u0131 saptamak i\u00e7in kullan\u0131l\u0131r.Buharla\u015ft\u0131r\u0131lm\u0131\u015f madde , elektronlarla bombard\u0131man edilerek art\u0131 y\u00fckl\u00fc iyonlar olu\u015fturulur.Bu iyonlar eksi y\u00fckl\u00fc bir levhaya do\u011fru \u00e7ekilerek bu levha \u00fczerinde bulunan dar bir aral\u0131ktan h\u0131zla ge\u00e7irilirler.<\/p>\n
\u0130yot demeti bundan sonra magnetik bir alan i\u00e7inden ge\u00e7irilir.y\u00fckl\u00fc tanecikler magnetik bir alan i\u00e7inde dairesel bir y\u00f6r\u00fcnge izlerler.Taneci\u011fin y\u00fck\u00fc artt\u0131k\u00e7a do\u011frusal y\u00f6r\u00fcngesinden sapma da artar.Bu nedenle , magnetik bir alanda art\u0131 y\u00fckl\u00fc bir iyonun izledi\u011fi dairesel y\u00f6r\u00fcngenin yar\u0131\u00e7ap\u0131 o iyonun e\/m de\u011ferine ba\u011fl\u0131d\u0131r.<\/p>\n
De\u011fi\u015fik e\/m de\u011ferine sahip iyonlar\u0131n bu son aral\u0131ktan ge\u00e7mesi ise magnetik alan \u015fiddeti veya iyonlar\u0131 h\u0131zland\u0131rmak i\u00e7in kullan\u0131lan voltaj ayarlanarak sa\u011flan\u0131r.B\u00f6ylece ayg\u0131ttaki farkl\u0131 iyon t\u00fcrlerinden her biri bu aral\u0131ktan ayr\u0131 ayr\u0131 ge\u00e7irilirler.Detekt\u00f6r her farkl\u0131 iyon demetinin \u015fiddetini \u00f6l\u00e7er ; bu iyon \u015fiddeti \u00f6rnekte bulunan izotoplar\u0131n ba\u011f\u0131l miktar\u0131na ba\u011fl\u0131d\u0131r.<\/p>\n
Atom Numaras\u0131 ve Periyotlar yasas\u0131<\/p>\n
19.y\u00fczy\u0131l\u0131n ba\u015flar\u0131nda kimyac\u0131lar elementler aras\u0131nda bulunan fiziksel ve kimyasal benzerliklerle ilgilendiler.1817 ve 1829 da Johann W. D\u00f6bereiner \u201ctriad\u201d lar ad\u0131n\u0131 verdi\u011fi element serileri (Ca,Sr,Ba;Li,Na,K;Cl,Br,I;S,Se,Te) hakk\u0131ndaki incelemelerini yay\u0131nlad\u0131 burada her seriyi olu\u015fturan elementler birbirine benzeyen \u00f6zeliklere sahip olup serideki ikinci elementin atom a\u011f\u0131rl\u0131\u011f\u0131 yakla\u015f\u0131k di\u011fer iki elementin atom a\u011f\u0131rl\u0131klar\u0131n\u0131n ortalamas\u0131na e\u015fittir.<\/p>\n
Bunu izleyen y\u0131llarda bir\u00e7ok kimyac\u0131 elementleri benzeyen \u00f6zellikleri a\u00e7\u0131s\u0131ndan s\u0131n\u0131fland\u0131rmay\u0131 denedi.1863-66 y\u0131llar\u0131nda John A. R. Newlands \u201coktavlar yasas\u0131\u201d n\u0131 \u00f6nerip geli\u015ftirdi.Newlands a g\u00f6re elementler atom a\u011f\u0131rl\u0131klar\u0131n\u0131n art\u0131\u015f s\u0131ras\u0131na g\u00f6re dizildiklerinde sekizinci element birinciye , dokuzuncu element ikinciye benziyor ve bu durum b\u00f6ylece devam ediyordu.Newlands bu ili\u015fkiyi m\u00fczik notalar\u0131ndaki oktavlara benzetti.Fakat ger\u00e7ek ili\u015fki Newlands\u2019\u0131n varsayd\u0131\u011f\u0131 kadar basit de\u011fildi.Newlands \u0131n \u00e7al\u0131\u015fmalar\u0131 dayanaks\u0131z bulunmu\u015f ve di\u011fer kimyac\u0131lar taraf\u0131ndan ciddiye al\u0131nmam\u0131\u015ft\u0131r.<\/p>\n
Elementlerin modern periyodik s\u0131n\u0131fland\u0131r\u0131lmas\u0131 Julius Lothar Meyer ve \u00f6zellikle Dimitri Mendeleev \u2018in \u00e7al\u0131\u015fmalar\u0131na dayan\u0131r.Mendeleev periyodik bir yasa \u00f6nerdi ; bu yasaya g\u00f6re elementler atom a\u011f\u0131rl\u0131\u011f\u0131 art\u0131\u015f\u0131na g\u00f6re incelendi\u011finde , \u00f6zelliklerindeki benzerlikler periyodik olarak tekrarlan\u0131r.Mendeleev in \u00e7izelgesinde benzer elementler grup ad\u0131 verilen dikey s\u00fctunlarda toplan\u0131r.<\/p>\n
Ayr\u0131ca Mendeleev in \u00e7izelgesinde hen\u00fcz bulunmam\u0131\u015f elementler i\u00e7in bo\u015f yerler b\u0131rakt\u0131 ve \u00e7izelgede olmayan elementlerden \u00fc\u00e7 tanesinin \u00f6zelliklerini \u00f6nceden belirtti.Hemen sonra Mendeleev in \u00f6ng\u00f6rd\u00fc\u011f\u00fc \u00f6zelliklerin \u00e7o\u011funa sahip olduklar\u0131 belirlenen Skandiyum,galyum ve germanyum elementlerinin bulunmas\u0131 periyodik sistemin do\u011fru oldu\u011funu g\u00f6sterdi.Asal gazlar\u0131n varl\u0131\u011f\u0131 Mendeleev taraf\u0131ndan \u00f6ng\u00f6r\u00fclmedi\u011fi halde bu elementler 1892-98 y\u0131llar\u0131 aras\u0131nda bulunduktan sonra periyodik \u00e7izelgedeki yerlerine olduk\u00e7a iyi bir \u015fekilde uydular.<\/p>\n
Periyodik \u00e7izelgedeki plana g\u00f6re K,Ni ve I elementlerinin atom a\u011f\u0131rl\u0131\u011f\u0131n\u0131n art\u0131\u015f\u0131na g\u00f6re belirlenmi\u015f dizili\u015finin d\u0131\u015f\u0131nda yer almamalar\u0131 gerekliydi.\u00d6rne\u011fi iyot atom a\u011f\u0131rl\u0131\u011f\u0131na g\u00f6re 52 numaral\u0131 element olmal\u0131yd\u0131.Fakat kimyasal a\u00e7\u0131dan benzedi\u011fi F,Cl ve Br elementleri ile ayn\u0131 gurupta olabilmesi i\u00e7in iyot keyfi olarak 53 numaral\u0131 element oldu.Periyodik s\u0131n\u0131fland\u0131rman\u0131n daha ayr\u0131nt\u0131l\u0131 olarak incelenmesi ile bir \u00e7ok ara\u015ft\u0131r\u0131c\u0131 periyodik \u00f6zelli\u011fin,atom a\u011f\u0131rl\u0131\u011f\u0131ndan \u00e7ok , ba\u015fka bir temel ba\u011fl\u0131 oldu\u011funa inand\u0131.Bu temel \u00f6zelli\u011finde o zamanlar periyodik sistemden \u00e7\u0131kar\u0131lan ve sadece bir seri numaras\u0131 olan atom numaras\u0131 ile ili\u015fkisi oldu\u011funu \u00f6\u011frendi.<\/p>\n
1913-14 y\u0131llar\u0131nda Henry G. J. Moseley in \u00e7al\u0131\u015fmalar\u0131 bu problemleri \u00e7\u00f6zd\u00fc.Y\u00fcksek enerjili katot \u0131\u015f\u0131nlar\u0131 bir hedefe odakland\u0131\u011f\u0131nda X-\u0131\u015f\u0131nlar\u0131 olu\u015fur.Bu X-\u0131\u015f\u0131nlar\u0131 \u00e7e\u015fitli dalga boylar\u0131ndaki bile\u015fenlere ayr\u0131labilir ve bu \u015fekilde elde edilen \u00e7izgi spektrumlar\u0131 da fotografik olarak kaydedilebilir.Hedef olarak de\u011fi\u015fik elementler kullan\u0131ld\u0131\u011f\u0131nda de\u011fi\u015fik X-\u0131\u015f\u0131nlar\u0131 spektrumlar\u0131 elde edilir ve her spektrum sadece birka\u00e7 karakteristik spektral \u00e7izgi i\u00e7eren X-\u0131\u015f\u0131nlar\u0131 spektrumu vard\u0131r.<\/p>\n
Moseley atom numaralar\u0131 13 ile 79 aras\u0131nda olan 38 elementin X-\u0131\u015f\u0131nlar\u0131 spektrumunu inceledi.Her elemen i\u00e7in o elemente kar\u015f\u0131l\u0131k gelen karakteristik spektrum \u00e7izgisini kullanan Moseley , elementin atom numaras\u0131 ile \u00e7izgi frekans\u0131n\u0131n kare k\u00f6k\u00fc aras\u0131nda do\u011frusal bir ili\u015fki oldu\u011funu buldu.Ba\u015fka bir de\u011fi\u015fle elementler atom numaras\u0131 art\u0131\u015f\u0131na g\u00f6re dizildi\u011finde spektrum \u00e7izgisi frekans\u0131n\u0131n karek\u00f6k\u00fc bir elementten di\u011ferine gittik\u00e7e sabit bir miktarda artar.<\/p>\n
Bundan dolay\u0131 Moseley X-\u0131\u015f\u0131nlar\u0131 spektrumuna dayanarak elementlerin do\u011fru atom numaralar\u0131n\u0131 tahmin edebildi.B\u00f6ylece atom a\u011f\u0131rl\u0131klar\u0131 kom\u015fu atomlar\u0131nkine uygun d\u00fc\u015fmeyen K,Ni ve I un s\u0131n\u0131fland\u0131r\u0131lmas\u0131 problemi de \u00e7\u00f6z\u00fcmlenmi\u015f oldu.Di\u011fer taraftan Moseley Ce den Lu e kadar olan seride 14 element bulunmas\u0131 ve bu elementlerin ve bu elementlerin periyodik \u00e7izelgede Lantan\u2019dan sonra gelmeleri gerekti\u011fini bildirdi.Moseley\u2019in diagramlar\u0131 ayr\u0131ca 79 numaral\u0131 elementten \u00f6nce hen\u00fcz o zamana kadar bulunmam\u0131\u015f 4 elementin var olmas\u0131 gerekti\u011fini de g\u00f6sterdi.Nihayet Moseley\u2019in \u00e7al\u0131\u015fmalar\u0131na dayanarak periyodik yasa \u201cElementlerin fiziksel ve kimyasal \u00f6zellikleri atom numaras\u0131n\u0131n periyodik fonksiyonudur\u201d \u015feklinde tekrar tan\u0131mland\u0131. <\/p>\n
Moseley in atom numaralar\u0131 ile Rutherford un tanecikleri sa\u00e7\u0131lma deneyinden hesaplad\u0131\u011f\u0131 \u00e7ekirdek y\u00fckleri olduk\u00e7a iyi bir uyum i\u00e7indeydi.buna dayanarak Moseley atom numaras\u0131n\u0131n atom \u00e7ekirde\u011finde bulunan art\u0131 birimlerin say\u0131s\u0131 oldu\u011funu \u00f6nerdi.<\/p>\n
Moseley ayr\u0131ca, atomda bir elementten di\u011ferine gidildik\u00e7e artan temel bir nicelik bulundu\u011funu ifade ederek bu niceli\u011fin ancak merkezdeki art\u0131 y\u00fckl\u00fc \u00e7ekirde\u011fin y\u00fckl\u00fc olabilece\u011fini belirtti.<\/p>\n
X-\u0131\u015f\u0131nlar\u0131 , g\u00f6r\u00fcn\u00fcr \u0131\u015f\u0131ktan \u00e7ok daha k\u0131sa dalga boylar\u0131na ve dolay\u0131s\u0131yla daha y\u00fcksek frekans ve enerjilere sahip elektro magnetik \u0131\u015f\u0131nlard\u0131r.Bir elementin x-\u0131\u015f\u0131nlar\u0131 spektrumunun olmas\u0131na hedef element atomlar\u0131nda meydana gelen elektron ge\u00e7i\u015flerinin sebep oldu\u011funa inan\u0131lmaktad\u0131r.X-\u0131\u015f\u0131nlar t\u00fcp\u00fcne katot \u0131\u015f\u0131nlar\u0131 , hedefteki atomlar\u0131n i\u00e7 kabuklar\u0131ndan elektronlar kopar\u0131rlar.D\u0131\u015f kabuktaki elektronlar i\u00e7 kabuklarda olu\u015fan bu bo\u015fluklar\u0131 doldurduklar\u0131 zaman x-\u0131\u015f\u0131nlar\u0131 yay\u0131nlan\u0131r.Bir atomda elektronun , y\u00fcksek bir enerji d\u00fczeyinden K d\u00fczeyine ge\u00e7mesi sonucu olduk\u00e7a bir b\u00fcy\u00fck bir miktarda enerji a\u00e7\u0131\u011fa \u00e7\u0131kt\u0131\u011f\u0131ndan , elde edilen radyasyonun frekans\u0131 y\u00fcksektir.Buna kar\u015f\u0131 gelen dalga boyu da x-\u0131\u015f\u0131nlar\u0131na \u00f6zg\u00fc olup k\u0131sad\u0131r.<\/p>\n
Bir elektron ge\u00e7i\u015fi s\u0131ras\u0131nda a\u00e7\u0131\u011fa \u00e7\u0131kan radyasyonun frekans\u0131 ayr\u0131ca atom \u00e7ekirde\u011findeki y\u00fcke ba\u011fl\u0131d\u0131r.A\u00e7\u0131\u011fa \u00e7\u0131kan bu enerjinin miktar\u0131 \u00e7ekirdek y\u00fck\u00fcn\u00fcn karesi ile do\u011fru orant\u0131l\u0131d\u0131r.\u00c7ekirde\u011fin y\u00fck\u00fc artt\u0131k\u00e7a a\u00e7\u0131\u011fa \u00e7\u0131kan enerji artar ve yay\u0131nlanan radyasyonun dalga boyu k\u0131sal\u0131r.Moseley in g\u00f6zlemleri de bu ili\u015fkiyi yans\u0131tmaktad\u0131r.<\/p>\n","protected":false},"excerpt":{"rendered":"
Maddenin temelinde atom ad\u0131 verilen \u00e7ok k\u00fc\u00e7\u00fck par\u00e7ac\u0131klardan olu\u015ftu\u011fu kavram\u0131 eski yunanl\u0131lara kadar uzan\u0131r. ATOM ve ELEKTRON Maddenin temelinde atom ad\u0131 verilen \u00e7ok k\u00fc\u00e7\u00fck par\u00e7ac\u0131klardan olu\u015ftu\u011fu kavram\u0131 eski yunanl\u0131lara kadar uzan\u0131r. Milattan \u00f6nce 5. y\u00fczy\u0131lda Leucippus ve Democritus maddenin sonsuz k\u00fc\u00e7\u00fck par\u00e7ac\u0131klara ayr\u0131lamayaca\u011f\u0131n\u0131 \u00f6ne s\u00fcrd\u00fcler.Onlar,bir madde daha k\u00fc\u00e7\u00fck par\u00e7alara b\u00f6l\u00fcnmeye devam edilirse en sonunda atomun …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1407,1403],"tags":[4787,3130,2261,2276,2137,4475,11755,2139,2138,2710],"class_list":["post-6414","post","type-post","status-publish","format-standard","hentry","category-fen-ve-teknoloji-odevleri","category-odevler","tag-atom-numarasi","tag-elektrik","tag-element","tag-iyot","tag-izotop","tag-katot","tag-moseley","tag-notron","tag-proton","tag-x-isinlari"],"_links":{"self":[{"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/posts\/6414","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/comments?post=6414"}],"version-history":[{"count":0,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/posts\/6414\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/media?parent=6414"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/categories?post=6414"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/tags?post=6414"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}