Question

(33) If force of attraction between the electron and nucleus in 2nd orbit of Liz isf, force of attraction if electron present in 1st orbit of His (A) OF (B) 127 (D)

JEE/Engineering Exams

Chemistry

Solution

186

5.0 (4 ratings)

formula of fore of atraition b/w elution and muleus is ( begin{aligned} F &=frac{k z e^{2}}{r^{2}} text { Where } k &=text { constant } z &=text { atomic number } end{aligned} ) = radius of sebit ( e= ) chage [ R_{n}=frac{a_{0} n^{2}}{z} quadleft(a_{0}=operatorname{comstant}right) ] Thus we get ( F=frac{k e^{2}}{a_{0}^{2}} frac{z^{2}}{n^{4}} ) for ( left[begin{array}{llll}2+ & 2 & =3 & text { and } & n=2end{array}, text { force }=fright. ) ( f=frac{k e^{2}}{a_{0}^{2}} frac{(3)^{3}}{(2)^{4}}=frac{k e^{2}}{a_{0}^{2}} frac{27}{16}= ) And for ( H, quad z=1, n=1 ) Folle ( quad=frac{k e^{2}}{a_{0}^{2}} frac{1^{3}}{1^{2}}=frac{k e^{2}}{a_{0}^{2}} ) ( begin{aligned} text { Fork } &=frac{k e^{2}}{a_{0}^{2}} frac{27}{16} times frac{16}{27} &=f times frac{16}{97}( text { foom } text { force } &=frac{16}{27} f end{aligned} )