If `r_(1)` and `r_(2)` are the radii of the atomic nuclei of mass numbers 64 and 125 respectively, then the ratio `(r_(1)//r_(2))` is

Options

A. `(64)/(125)`
B. `sqrt((64)/(125))`
C. `(5)/(4)`
D. `(4)/(5)`

Answer

D

Explanation

Nuclear radii, `r=r_(0)(A)^(1//3)`
`therefore (r_(1))/(r_(2))=((A_(1))/(A_(2)))^(1//3)=((64)/(125))^(1//3)=((4^(3))/(5^(3)))^(1//3)=(4)/(5)`.