Calculate the velocity of an electron present in third orbit of H atom. Also calculate number of revolutions per second round the nucleus.

Explanation

Radius of 3 rd orbit
`=3^(2)xx0.529xx10^(-8)=4.761xx10^(-8)cm`
We know that, `mvr=(nh)/(2pi)` or `v=(nh)/(2pimr)`
`=(3xx6.624xx10^(-27))/(2xx3.14xx(9.108xx10^(-28))xx(4.761xx10^(-8)))`
`=0.729xx10^(8)cm//sec`
Time taken for one revlution `=(2pir)/(v)`
Number of revolutions per second
`=(1)/((2pir)/(v))=(v)/(2pir)`
`=(0.729xx10^(8))/(2xx3.14xx4.761xx10^(-8))`
`=2.4xx10^(-14)"revolution/sec"`.