R = R 0 A 1 3 ( R 0 = constant , A = mass no . ) . Taking the above relation, show that the nuclear density does not depend upon the mass number A .

Given the relation R = R 0 A 1 3 ( R 0 = constant , A = mass no . ) Nuclear Density:-Nuclear density is the density of the nucleus of an atom. Let the mass of each nucleon be m , then the mass of nucleus = m A Volume of nucleus = 4 πR 3 3 = 4 π R o A 1 3 3 3 Density of Nuclear matter = mass of nucleus Volume of nucleus ρ = 3 mA 4 πA R o 3 = 3 m 4 π R o 3 . Each term in the above expression is constant, therefore, the nuclear density is also constant and is independent of the mass number,

Draw the curve showing the variation of binding energy per nucleon as a function of mass number A . Explain the stability of nucleus from the curve

The net binding energy associated with a given nucleus is equal to that of the difference between the nuclear attraction and the disruptive energy of the electric force The graph between the binding energy per nucleon and the atomic number A have shown above. The main feature of this curve is (i) the binding energy per nucleon, is practically constant, for ( 30 < A < 170 ). The curve has a maximum of about 8 . 75 MeV for A = 56 ( Fe ) and has a value of 7 . 6 Mev for A - 238 . BE/ nucleons are lower for both light nuclei and heavy nuclei.( A < 30 and A > 170 ) The greater the binding energy per nucleon in a nucleus, the greater is the minimum energy needed to remove a nucleon from the nucleus. Thus, binding energy per nucleon indicates the stability of a nucleus It is observed that The binding energy of very light nuclei is very low. If two very light nuclei ( A < 10 ) join to form a heavier nucleus. The binding energy per nucleon of the fused heavier nuclei is more than the binding energy per nucleon of the lighter nuclei. This means that the final system is more tightly bound than the initial system. Again energy would be released in such a process of fusion.

E M B I B E

Previous Years' Solved Papers: Physics West Bengal Board 12>Chapter 22 - Nuclear Physics>West Bengal Board-2018>Q 3

EASY

12th West Bengal Board

IMPORTANT

Earn 100

What is meant by the activity of a radioactive substance? write it's S.I. unit.

Important Questions on Nuclear Physics

HARD

12th West Bengal Board

IMPORTANT

Previous Years' Solved Papers: Physics West Bengal Board 12>Chapter 22 - Nuclear Physics>West Bengal Board-2018>Q 4

Half life of a radioactive substance is $30 days$ . The number of atoms in the substance is $10^{12}$ . How many disintegrations of atoms per second occur?

EASY

12th West Bengal Board

IMPORTANT

Previous Years' Solved Papers: Physics West Bengal Board 12>Chapter 22 - Nuclear Physics>West Bengal Board-2019>Q 5

How many $α and β$ particles are emitted when $U^{238}$ changes to ${Pb}^{206}$ due to radioactivity? The atomic number of $U^{238}$ land ${Pb}^{92}$ is $92$ and $82$ respectively.