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© Kuthorford!s atomic model Based On the c_« altering expeviment Rutherford explain tho probable Structuyo af atom as descsibed efor Ry ; ; I. Almost whole of the mass of any alom and posit An extromely smelt Volume. sie called this veq Nucleus, ® the wucleue ig survOunded by yve Ja charged particles called electron. Eleetrong yovelyg around +h i high Sp2ea In . @ mucleus with yery hig Cweular paths “These paths ave called drbit. d . Coulombic force o attraction between Cyvel charged electron and CNely “oe Ara that aets aloug dy aie toward the ante au Centrifugal force due 40 the moving body (It acts along b redius but Away from the Centve - direction, these two forces alawce ach sie 50 that the eledrons KeoP On moving around the Nucleus mm a de wite Circulay path. . Limi tation Of Rutherford's atomic model : Rutherford atomie vnodel suffers from Two main defects I. According 410 Ruth exford elecdyons yovolve avound the nucleus in feed Paths Called orbits. heeording fo Maxwell, aecelevated charged fartieles emit electromagnetic vadiation aud hone an electvan revolying around the mucleus should emit elecyomaguetic radiation in form ¢ energy, Thus electyan will lase their energy and Gradually reduce the radius Gnd finally Collapse 40 tho wucleus ina Spiral Way, Thus the modo) Can nok Justify the stability of an atom, Q. Ruthevfoyd's atomic modal does not extla any arrangement of electrons in orbit, soit yomains meoimplete. St is One Of the mayor limitations of Rutherford's atomic mode}. Planck's quantum theory The main featuyes of Planck's quantum theory are given below: a) Radiant energy 18 not emitted or absorbed Continuously but discontinuously in the form of sina packe} of ewrqy called quanta. Fach wave packet dr quanta is associated with a definite Oamount of enoray, the quanta of light energy Ate called Photons ie charge ‘5 concentrated ion of the atom as il ‘ tum 4 yadi ation MI aun Of energy associated with @ quan ] * el norte the hequency af vadiation md IS exProssp] as Coo yt nF =hy tore h 1s Called Planck's constant and ‘y’ 18 the frequency of Vadiaton , h= 6 £26x [9-34 Ts of &baex (QF y-5 ") A body Can, emit or absorb Lnergy Only in terms of Whole Number multible of quantum {2 E= nhy Where , N-4,9,% .... ete, "Key concept and immbortant information cl =} , Re Fn Rae ; = 10m a = lm (ll Centr botal foree = My ¥ Cleve 1% KIO Py CY) Bohy'e theory is Applicable to H- like Species containing One elecdy, On only, eg Lite tet BeotS ete, V) Fe nhe A Che= axit*almest) 
