JEE Main20258 Apr 2025Evening ShiftPhysicsNuclear PhysicsActual
For a nucleus of mass number A and radius R , the mass density of nucleus can be represented as
Options
- AA ^3
- BA ^ 1 3
- CA ^ 2 3
- DIndependent of A
Correct answer
D. Independent of A
Step-by-step solution
The mass density ( ) of a nucleus is defined as the ratio of its mass to its volume: = Mass of nucleus / Volume of nucleus For a spherical nucleus with radius R , the volume is: Volume =(4 / 3) R^3 The mass of the nucleus is related to the mass number A : Mass - A m _u (where m_u is the atomic mass unit, approximately 1.66 10⁻²⁷ ~kg ) Therefore: = ( A m _ u ) / [(4 / 3) R ^3 ] Now, there's an important relationship between the mass number A and nuclear radius R. Empirically, it has been found that: R = Ro * ~A ^ (1