Question

The radius of germanium (Ge) nuclide is measured to be twice the radius of  `""^9""_4"Be"`. The number of nucleons in Ge will be ____________.

Options

• 72

• 73

• 74

• 75

Answer 1

The radius of germanium (Ge) nuclide is measured to be twice the radius of  `""^9""_4"Be"`. The number of nucleons in Ge will be 72.

Explanation:

`"R" = "R" _0 "A"^(1//3)`

`therefore "R" _"Ge"/"R" _"Be" = ("A"_"Ge"/"A"_"Be")^(1//3)`

`therefore (2"R" _"Be")/"R" _"Be" xx ("A"_"Be")^(1//3)`

` = ("A"_"Ge")^(1//3)`

`therefore 2^3 xx 9 = "A"_"Ge"`

`therefore "A"_"Ge" = 72`