© examsnet.com
Question : 30
Total: 35
(a) (i) Distinguish between nuclear fission and fusion giving an example of each.
(ii) Explain the release of energy in nuclear fission and fusion on the basis of binding energy per nucleon curve.
OR
(b) (i) How is the size of a nucleus found experimentally? Write the relation between the radius and mass number of a nucleus.
(ii) Prove that the density of a nucleus is independent of its mass number.
(ii) Explain the release of energy in nuclear fission and fusion on the basis of binding energy per nucleon curve.
OR
(b) (i) How is the size of a nucleus found experimentally? Write the relation between the radius and mass number of a nucleus.
(ii) Prove that the density of a nucleus is independent of its mass number.
Solution: 👈: Video Solution
(a) (i) Nuclear fission & fusion:
(ii) In nuclear fusion, the binding energy of the products is greater than the binding energy of reactants.
In nuclear fission, binding energy of fragments is greater than the binding energy of the parent.
This difference in binding energy is released in form of energy.
OR
(b) (i) Experimental determination of size of nucleus:
Size of nucleus was determined experimentally by Rutherford by his alpha particle scattering experiment.
In the experiment, a gold foil of thickness2.1 × 10 − 7 α 83 Bi 214
Scatteredα ZnS
It was observed that most of theα
About14 % α 1 0
1 out of8000 α 90 ∘
Very fewα 180 ∘
From these observations Rutherford calculated the impact parameter and distance of closest approach and concluded that the size of nucleus lies between10 − 15 m 10 − 14 m
Relation between radius and mass number:
r = R 0 A 1 ∕ 3 ( where R 0 = 1.25 fm )
(ii) Density of nucleus is independent of mass number:
ρ =
or,ρ =
or,ρ =
(since r = R 0 A 1 ∕ 3 )
∴ ρ =
Hence, it is independent of mass number.
| Nuclear fission | Nuclear fusion |
|---|---|
| Heavy nucleus splits into comparatively lighter nuclei. | Lighter nuclei fuse to form comparatively heavier nuclei. |
| Energy released is less than that of fusion. | Energy released is more than that of fission. |
| Does not naturally occur. | Occur naturally in stars. |
| Comparatively less amount of energy required to start the process. | Huge amount of energy is required to start the process. |
| Application: Atomic bomb | Application: Hydrogen bomb |
| | Example: |
(ii) In nuclear fusion, the binding energy of the products is greater than the binding energy of reactants.
In nuclear fission, binding energy of fragments is greater than the binding energy of the parent.
This difference in binding energy is released in form of energy.
OR
(b) (i) Experimental determination of size of nucleus:
Size of nucleus was determined experimentally by Rutherford by his alpha particle scattering experiment.
In the experiment, a gold foil of thickness
Scattered
It was observed that most of the
About
1 out of
Very few
From these observations Rutherford calculated the impact parameter and distance of closest approach and concluded that the size of nucleus lies between
Relation between radius and mass number:
(ii) Density of nucleus is independent of mass number:
or,
or,
Hence, it is independent of mass number.
© examsnet.com
Go to Question: