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 3rd orbit `=3^(2) xx 0.529 xx 10^(-8)`
`= 4.761 xx 10^(-8)cm`
`mvr = n(h)/(2pi) rArr v = (nh)/(2pimr)`
`= (3 xx 6.624 xx 10^(-27))/(2xx 3.14 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 revolutions per second
`= (1)/((2pir)/(v)) = (v)/(2pir) = (0.729 xx 10^(8))/(2xx 3.14 xx 4.761 xx 10^(-8))`
`= 2.4 xx 10^(14)` revolution/sec