Class-10 Nuclear Physics Goyal Brother Prakashan ICSE Solutions Ch-11. We Provide Step by Step Answer of Exercise, MCQs Questions of Exercise-1 & 2. Goyal Brothers Nuclear Physics ICSE Class-10 . Visit official Website CISCE  for detail information about ICSE Board Class-10 Physics.

## Class-10 Nuclear Physics Goyal Brother Prakashan ICSE Solutions Ch-11

-: Select Topics :-

Exercise-1

MCQ -1

### Exe-1 Class-10

Class-10 Nuclear Physics Goyal Brother Prakashan ICSE Solutions Ch-11

Page-196,197

Question 1.
Give at least two differences between a chemical change and nuclear change.
Chemical change

1. Change in number of orbital electrons takes place.
2. Requires energy of few eV for a chemical reaction to take place.
3. Number of atoms of each kind is conserved in reactants and products

Nuclear change

1. Change in number of nucleons takes place.
2. Nuclear change require much higher energy of the order of 106 times as compared to chemical change.
3. Atomic number and mass number is conserved.

Question 2.
State Rutherford and Soddy’s Laws of natural radioactive decay for
(1) alpha emission
(2) beta emission.
(1) Rutherford and Soddy’s Law of Alpha Emission : “When a radio-active nuclide ejects on alpha particle (α) i.e. 42H, its mass number decreases by 4 and atomic number decreases by 2 such that the position of daughter nuclide is two places behind in the predictable as compared to the parent nuclide ?

(2) Rutherford and Soddy’s Law of Beta Emission : “When a radio-active nuclide ejects a beta particle, its mass number remain Unaffected but Atomic Number Increases by one such that the position of the daughter nuclide is one place Ahead in the periodic table as compared to the parent nuclei.” The daughter product is Isobar.

Question 3.
Thorium isotope 22390Th undergoes two successive β-decays. Find the mass number and atom C number after the decay. Also represent the above decays in the form of a nuclear equation.
After first p decay mass number remains same i.e. 223 but Atomic number increases by 1 and becomes 91

Two successive P radiations cannot take place. He a radiation takes place which does not change mass number or atomic number.
Now second β decay

mass number remains 223 atomic number becomes 92.

Question 4.
How is the ionising and penetrating powers of α, β and γ radiations compared with each other ?
Comparison of Ionising power of α, β,γ Heavier particle has high ionising power.
a → 10,000 times of α and 100 times of β
P → 100 times of α
∴ Maximum ionising power a, minimum ionising power γ.
Comparison of Penetrating power of α, β and γ
Light particle has maximum speed hence maximum penetrating power.
α has very large penetrating power up to a few hundred meter in air.
α has small penetrating power (being very heavy) 3 to 8 cm in air
β- has large penerating power up to few meter in air α < β < γ.

Question 5.
When does the nucleus of an atom tend to be radioactive?
Nucleus of an atom become radio-active when increase in nuclear force.
PACE WITH INCREASE IN THE REPULSIVE FORCE :
i.e.when there are too many neutrons compared to protons or too many protons compared to neutrons in the nucleus of atom. Or The nucleus of the atom becomes radioactive if it is a radio-isotope, i.e. number of neutrons in the nucleus exceeds the number of protons inside it.
For example :

Question 6.
Radioactive sodium 2411Na changes to stable 2412Th Which particle does it eject ?
P-particle  (0-1e )
∴ There is no change in mass number but atomic number of daughter nucleus magnesium increases by one.

Question 7.
A radioactive element AzX loses two successive β-particles and then an alpha particle, such that the resulting nuclide PQY  is Calculate the values of P and Q.

When AzX loses first β-particle atomic number of daughter nucleus Y increases by one and mass number remains the same

When Az+1X  loses another β-particle changes to daughter nucleus Z and atomic number again increases by one and mass number still remains the same A.

Question 8.
(a) An imaginary radioactive particle 23592X decays to form elements X1, X2, X3, X4, X5 and X6 by ejecting 2 beta particles, followed by an alpha particle and again 2 beta particles followed by an alpha particle. Represent the above in the form of nuclear equations. What is the mass number of X6 ?
(b) List the isotopes and isobars formed in the above nuclear reactions.
(a) 23592X when α β particle is emitter mass number does not change but atomic number increases by 1 (isobar)
∴ When 2 successive β particles decay mass number does not change (isobar) but atomic number increases by 2.
Then α-particle decays, mass number decreases by 4 and atomic number decreases by 2.
Ultimately when 2 β particles decays and la-particle decays

This means to change 23592X to 23592X1 here, atomic number remains same but mass number
decreases by 4
∴ In 6 steps [X → X1 → X2 → X3 →X4 →X5 →X5]
Atomic number remains same but mass number decreases by
6 x 4 = 24

(b) After every β decay isobar is formed and after α-decay isotope is formed
∴ Total 12 isobars and 6 isotopes are formed.

Question 9.
Give one example of nuclear fission.
Nuclear power station is example of nuclear fission. Controlled chain reaction takes place and electricity is produced.

Question 10.
Indicate the missing particle in the following reaction :

Question 11.
Complete the statement given below :
Splitting of nucleus into two nearly lighter nuclei is called
Splitting of nucleus into two nearly lighter nuclei is called nuclear fission.

Question 12.
Name the fuel generally used in nuclear reactors.
Enriched Uranium 23592U is used as fuel in nuclear reactor.

Question 13.
Give one example of a controlled and uncontrolled nuclear fission reaction.
Example of:

1. Controlled nuclear fission reaction is to generate electricity in nuclear thermal plant.
2. Uncontrolled nuclear fission reaction is production of ATOM BOMB.

Question 14.
Name the isotopes of an element which are used in fusion
ISOTOPES of ELEMENT HYDROGEN are :
11H protium
21H deuterium
31H Tritium

Question 15.
What is meant by nuclear chain reaction ? What happens, if this reaction goes out of control ?
NUCLEAR CHAIN REACTION : A piece of URANIUM consists of millions of uranium atoms. When a slow moving neutron is bombarded, it produces three neutrons, if these neutrons are utilised to break further uranium atoms, 9 neutrons are produced and in this way a kind of chain reaction takes place with release of large amount of energy and reaction becomes uncontrolled. This results in atom bomb.

Question 16.
The mass numbers of three elements A, B and C are 3, 180 and 235 respectively. Which one is suitable for making atomic bomb?
Element C with atomic number 235 is suitable for making atom bomb.

Question 17(a).
Define nuclear fusion.
NUCLEAR FUSION : The process of combining LIGHTER NUCLEI (Atomic weight less than 20) into heavier nuclei is called nuclear fusion

Question 17(b).
Which of the two, fission or fusion is a nuclear chain reaction?
Fission is nuclear chain reaction.

Question 18.
Why can nuclear fusion and possible to generate electricity?
It is not easy to start a fusion reaction as to fuse HYDROGEN atom minimum temperature of 1000000 °C is required which is not possible to create in laboratory. Controlled fusion reaction is not possible so far.

Question 19.
Give any two differences between nuclear fusion and nuclear fission.
Nuclear Fusion

1. Two light nuclei fuse to form a heavy nucleus.
2. Cannot be controlled to generate electricity position.

Nuclear Fission

1. A heavy nucleus splits to form two smaller nuclei.
2. Can be controlled and is used to generate electricity.

Question 20.
Write nuclear equations for the fusion of
(a)   2 deuterium atoms
(b)   one hydrogen and one tritium atom.

### Multiple Choice Questions-1

Class-10 Goyal Nuclear Physics ICSE Physics Solutions Ch-11

1. The atoms of same element having same atomic number, but different atomic masses are called :
(a) isotopes
(b) isobars
(c) isotones
(d) both (a) and (b)

2. When an element gives out high energy radiations on its own, the change which takes place is :
(a) physical change
(b) chemical change
(c) nuclear change
(d) none of these

3. The atoms of different elements having same mass number, but different atomic numbers are called :
(a) isotopes
(b) isotones
(c) isobars
(d)  none of these

(a) affect photographic plates
(b) ionise the gases
(c) are affected by electrostatic and magnetic fields
(d) all of these

5. A radioactive substances emits :
(a) simultaneously α, β and γ radiations
(c) in the order of α, β and γ particles
(d) X-rays and γ -rays

6. During α-emission :
(a) the mass number and atomic number of an atom decrease by 2 a mu.
(b) the mass number decreases by 4 amu and atomic number decreases by 2 amu.
(c) the mass number remains unchanged, but atomic number decreases by 2 amu.
(d) the mass number decreases by 4 amu and atomic number remains unchanged.

7. During β-emmision :
(a) the mass number remains unchanged, but atomic number increases by 1 amu.

(b) the mass number remains unchanged, but atomic number decreases by 1 amu.
(c) the mass number increases by 1 amu, but atomic number remains same.
(d) the mass number and atomic number decrease by 1 amu.

8. During β-emission an electron is ejected from the atom of radioactive substance. The electron is ejected from the:
(a) the outermost orbit of atom
(b) the innermost orbit of atom
(c) the nucleus of the atom
(d) none of these

9. Which of the following radiation is most ionising ?
(a) α-particles
(b) β-particles
(d) X-rays

10. Which of the following radiation is most penetrating ?
(a) αparticles
(b) β-particles
(d) X-rays

11. Which of the following radiation gets deflected most in electric or magnetic field ?
(a) αparticles
(b) β-particles
(d) X-rays

-: End of Nuclear Physics : Goyal Brothers  ICSE Physics Class-10 Solution :-

Thanks

$${}$$