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Explainaccordingto Bohr.smodelof hydrogen(1)principalquantum number (ii)Readingofstationaryorbit(r ) (iii) Energyof stationarystate(iv)isoelecronicionof h (v ) Velocityofelectron |
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Answer» Solution :(i) Principalquantumnumber : The stationarystatesfor ELECTRONARE numberedn = 1,2,3Theseintegralnumberare knowas principalquantumnumbers. (ii) Stationaryorbitradili (r ) : The radil of thestationarystatesareexpressed as : `r_(n) = n^(2) a_(0) ` where`a_(0)= 52.9 pm` Theradiusof the firststationary(n-1)statecalledthe Bohr.sorbitis 52.9 pm Normallythe elecrronin thehydrogenatomis foundin thisorbit(thatis n=1) (iii)energyof stationarystate: Themostimportantpropertyassociatedwith theelectronis the energyofits stationarystateit is GIVENBY the expression. Whenthe ELECTRONIS freethe influence ofnucleusthe energyis takenas zero. Theelectronin thissituationis associatedwith thestationarystateof principalQuantumnumber =in thissituation electronis FREE from Hatomand become`(H^(+))` hydrogen ion. Whenthe electron isattracted by thenucleusand itsenergyis lowered . Thatis thereason for the presenceof negativesighin equationanddepicts itsstabilityrelativeto thereferencestateof zeroenergyand n=soEnergyof electronsin atomis lessthan thefreeelectron. `E_(prop)= 0`  (iv)boh.stheoryforisoelectronicion ofhydrogen Bohr.stheorycan also appliedto theionscontainingonlyone electronsimilar to thatpresent in hydrogenatom. Theenergiesof thestationarystatesknownas hydrogenlikespecies) are givenby theexpression. `E_(n)= - 2 .18 xx10^(-18).(z^(2))/( n^(2)) 1` Wherez=atomicnumber=2,3,4for theheliumlithium berylliumrespectively Fromtheaboveequationsit isevident thatthevalue ofenergybecomesmorenegativeand that ofradiusbecomessmaller withincreaseof Z (v )VELOCITYOF electron It is alsopossibleto calculateteh velocitiesofelectronsmovingin theseorbits , Althoughthe preciseequationis notgivenherequalitativelythemagnitudeof velocitypositivechargeon thenucleusanddecreaseswithincreaseof principalquantum number |
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