The speed of electron in the second orbit of `Be^(3+)` ion will be

Options

A. `( C)/(137)`
B. `( 2 C)/(137)`
C. `(3 C)/(137)`
D. `(4 C)/(137)`

Answer

B

Explanation

`v = Z [(1)/(137) (c)/(n)]`
`= 4 xx (1)/(137) xx (c)/(n)`
`(2 c)/(137)`