Calculate frequency of revolution of electrons in `4^(th)` Bohr orbit of `Be^(+3)` ion. Given that `(pi^(2)me^(4)k^(2))/(h^(3))=1.62xx10^(15) sec^(-1)`. Symbols have usual meaning. Express your answer in terms of `10^(15) sec^(-1)`.

Answer

2

Explanation

`f=((4pi^(2)mK^(2)e^(4))/(h^(3))) xx(Z^(2))/(n^(2))`
`=4xx1.62xx10^(15) xx(4^(2))/(4^(2)xx4) =1.62xx10^(15) =1.62 =2`