Calculate the velocity of an electron placed in (III) orbit of H-atom . Also calculate the no . of revalution /sec around the nucleus .

Explanation

Radius of 3rd orbit `=3^(2) xx 0.529 xx 10^(-8)`
`=4.761 xx 10^(-8) cm`
`mvr=n (h)/(2pi)` or `v= (nh)/(2pi mr)`
`(3 xx 6.624 xx 10^(-27) )/(2xx3.14 xx (9.108 xx 10^(-28) ) (4.761 xx 10^(-8) ))`
`= 0.729 xx 10^(8) cm//sec`
Time taken for one revolution `= (2pir)/(v)`
Number of revolution per second
`= (1)/((2pir)/(v) ) = (v)/(2pir) = (0.729 xx 10^(8) )/(2 xx 3.14 xx 4.761 xx 10^(-8))`
`= 2.4 xx 10^(14)` revolution/sec