(i) What characteristic property of nuclear force explains the constancy of binding energy per nucleon `(BE//A)` in the range of mass number 'A' lying `30 lt A lt 170` ?
(ii) Show that the density of nucleus over a wide range of nuclei is constant-independent of mass number A.

Explanation

(i) Saturation is short range nature of nuclear forces.
(ii) Nuclear density `rho=("Mass of nucleus")/("Volume of nucleus")`
`rho=(mA)/((4)/(3)pi R^(3))` (where m=mass of one nucleon, A=mass number)
`R= R_(0)A^(1//3)="Radius of nucleus"`
`rho=(mA)/((4 pi)/(3)(R_(0)A^(1//3))^(3))=(3 m cancelA)/(4pi R_(0)^(3) cancelA) implies rho =(3m)/(4pi R_(0)^(3))`
This expression is independent of mass number A and is constant.