WBBSE Class 10 Physical Science MCQ Questions Chapter 7 Atomic Nucleus

Well structured WBBSE Class 10 Physical Science MCQ Questions Chapter 7 Atomic Nucleus can serve as a valuable review tool before exams.

Atomic Nucleus Class 10 WBBSE MCQ Questions

Multiple Choice Questions :

Question 1.
Radioactive disintegration differs from a chemical change in being
(A) a nuclear process
(B) an exothermic process
(C) a sponteneous process
(D) a unimolecular first order reaction
Answer:
(A) a nuclear process

Question 2.
The phenomenon of radioactivity was first discoverd by –
(A) Rutherford
(B) Henry Becquerel
(C) Niels Bohr
(D) Madam curie
Answer:
(D) Modam curie.

Question 3.
a-rays consist of a stream of –
(A) H⁺
(B) He²⁺
only electrons
(D) only neutrons
Answer:
(B) He

Question 4.
Which of the following radiations, the one most easily stopped by air is –
(A) X-rays
(B) α-rays
(C) β-rays
(D) γ-rays
Answer:
(A) X-roys

Question 5.
γ-rays –
(A) consist of (+) ve particles
(B) are energy waves
(C) are deflected by an electric field
(D) have mass
Answer:
(B) are energy waves

Question 6.
A device used for the measurement of radioactivity is –
(A) mass spectrometer
(B) cyclotron
(C) nuclear reactor
(D) G-M-counter
Answer:
(D) G-M-counter

Question 7.
If a radioactive element is placed in an evacuated container, its rate of disintegration –
(A) will be increased
(B) will be decreased
(C) will change very slightly
(D) will remain unchanged
Answer:
(D) will remain unchanged

Question 8.
Emission of a β-particle by an atom of an element results in the formation of its
(A) isotope
(B) isomer
(C) isobar
(D) isomorph
Answer:
(C) isobar

Question 9.
Which of the following combinations will give the most stable nuclei?
(A) Odd Z and odd N
(B) Even Z and even N
(C) Odd Z and even N
(D) Even Z and odd N
Answer:
(B) Ever Z and even N

Question 10.
Stable nuclides cannot be obtained for –
(A) Z = 43, N = 35
(B) Z = 61, Z = 89
(C) A > 209
(D) All of these
Answer:
(D) All of thest

Question 11.
Which of the following nuclei are stable?
(A) \({ }_{28}^{60} \mathrm{Ni}\)
(B) \({ }_6^{11} \mathrm{C}\)
(C) \({ }_92²³3} \mathrm{U}\)
(D) \({ }_4^{8} \mathrm{Be}\)
Answer:
(D) \({ }_4^{10} \mathrm{Be}\)

Question 12.
Which of the following nuclel is unstable ?
(A) \({ }_5^{10} \mathrm{C}\)
(B) \({ }_7^{14} \mathrm{N}\)
(C) \({ }_8^{16} \mathrm{O}\)
(D) \({ }_4^{10} \mathrm{Be}\)
Answer:
(D) \({ }_4^{10} \mathrm{Be}\)

Question 13.
One becquerel of radioactivity of equal to –
(A) one disintegation/s
(B) two disintegration/s
(C) 6.023 × 10²³ disintegration/s
(D) three disintegration/s
Answer:
(A) one disintegation/s

Question 14.
The emission of beta-particles is from-
(A) the valence shell of an atom
(B) the inner shell of an atom
(C) the nucleus due to the nuclear conversion proton → neutron + electron
(D) the nucleus due to the nuclear conversion neutron → proton + electron.
Answer:
(D) the nucleus due to the nuclear conversion neutron → proton + electron.

Question 15.
Which of the following processes causes the emission of an x-ray?
(A) Alpha emission
(B) Gamma emissionz`
(C) Positron emission
(D) Electron capture
Answer:
(D) Electron capture

Question 16.
Loss of β-particle is equivalent to –
(A) increase of one proton
(B) decrease of one neutron
(C) combination of both (A) and (B)
(D) None of the above
Answer:
(C) combination of both (A) and (B)

Question 17.
Choose the incorrect one –
(A) 1 curie = 3.7 × 10¹⁰ ds^-1
(B) 1 rutherford = 10⁶ ds^-1
(C) 1 becquerel = 1 ds^-1
(D) 1 fermi = 10³ ds^-1
Answer:
(D) 1 fermi = 10³ ds^-1

Question 18.
Which of the following is the man-made redioactive disintegration series?
(A) Thorium series
(B) Neptunium series
(C) Uranium series
(D) Actinium series
Answer:
(B) Neptunium series

Question 19.
Temperature has no effect on the rate of decay because –
(A) nuclear energies are low
(B) radioactive decay is a statistical process
(C) nuclear energies are very high
(D) radioactive decay follow exponential law
Answer:
(C) nuclear energies are very high

Question 20.
Mark the correct relation-
(A) N₀ = N e ^λt
(B) τ = 1.44 t_0.5
(C) N = N₀ (\(\frac{1}{2}\))ⁿ
(D) t_0.5 = λ ln²
Answer:
(D) t_0.5 = λ ln²

Question 21.
Which one of the following is not a synthetic elements?
(A) U
(B) Cm
(C) Np
(D) PU
Answer:
(A) U

Question 22.
Choose the natural element among the following –
(A) technetium
(B) neptunium
(C) astatine
(D) uranium
Answer:
(D) uranium

Question 23.
Which is not correctly matched here?
(A) Polonium was discovered by Madam curies
(B) Natural radio activity discovered by Henry Becqueral
(C) Maximum penetration power is of α-rays
(D) γ-rays was discovered by willard
Answer:
(C) Maximum penetration power is of α-rays

Question 24.
Positron is the name given to an atom like combination formed between-
(A) a positron and a proton
(B) a positron and a neutron
(C) a positron and α-partical
(D) a positron and an electron
Answer:
(D) a positron and an electron

Question 25.
Which of the following are β – emitters ?
(A) Carbon-14
(B) Cobalt – 60
(C) Tritium – 3
(D) All of these.
Answer:
(D) All of these

Question 26.
Which of the following has highest value for its radioactivity ?
(A) 1 g of Ra
(B) 1 g of Ra so₄
(C) 1 g of Ra Br₂
(D) All of the above have same value
Answer:
(A) 1 g of Ra

Question 27.
Which of the following are α-emitters ?
(A) Helium-5
(B) Tritium
(C) Polonium-212
(D) None of these
Answer:
(C) Polonium-212

Question 28.
In radioactive decay, the emitted electrons come from the-
(A) innermost shell of the atom
(B) outermost shell of the atom
(C) K-shell of an atom
(D) decay neutrons in the nucleus.
Answer:
(D) decay neutrons in the nucleus.

Question 29.
Which emits b-particle?
(A) \({ }_1^3 \mathrm{H}\)
(B) \({ }_6^{14} \mathrm{C}\)
(C) [\({ }_{19}^{40} \mathrm{~K}\)
(D) All of these.
Answer:
(D) All of these.

Question 30.
\({ }_1^3 \mathrm{Al}\) is a stable isotope. It is expected to disintegrate by-
(A) α-emission
(B) β^– -emission
(C) β⁺-emission
(D) proton emission
Answer:
(B) β-emission

Question 31.
Of the following which is not used as a moderator in a nuclear reactor?
(A) Heavy water
(B) Graphite
(C) Beryllium
(D) Sodium
Answer:
(D) Sodium

Question 32.
Control rods used in the nuclear reactor are made of-
(A) nickel
(B) graphite
(C) iron
(D) cadmium
Answer:
(D) cadmium

Question 33.
The moderator used in atomic pile is-
(A) heavy water
(B) uranium
(C) cadmium
(D) iron
Answer:
(A) heavy water

Question 34.
Control rods of nuclear reactor are made up of-
(A) Cd
(B) copper
(C) diamond
(D) graplite
Answer:
(A) Cd

Question 35.
In a nuclear reactor, heavy water is used-
(A) to provide high speed neutrons
(B) to increase the speed of neutrons
(C) to capture neutrons produced by nuclear fission
(D) to transfer the heat from the nuclear reactor
Answer:
(D) to transfer the heat from the nuclear reactor

Question 36.
Near nuclear reactor there is-
(A) large neutron flux
(B) large proton flux
(C) large γ-ray flux
(D) large particles flux
Answer:
(A) large neutron flux

Question 37.
Which of the following isotopes is used in establishing the reaction mechanism of photosynthesis in plants?
(A) \({ }_6^{12} \mathrm{C}\)
(B) \({ }_6^{13} \mathrm{C}\)
(C) \({ }_6^{14} \mathrm{C}\)
(D) \({ }_1^{2} \mathrm{H}\)
Answer:
(C) \({ }_6^{14} \mathrm{C}\)

Question 38.
Which of the following radioactive elements is soluble in water?
(A) Radium
(B) Radon
(C) Technetium
(D) Tritium
Answer:
(B) Radon

Question 39.
Decrease in atomic number is not observed during-
(A) α-emission
(B) β-emission
(C) positron
(D) electron capture
Answer:
(B) β-emission

Question 40.
The relative penetrating power of α, β, γ and neutron (n) follows the order-
(A) α > β > γ > n
(B) n > γ > β > α
(C) β > α > n > γ
(D) None of these
Answer:
(B) n > γ > β > α

Question 41.
Which of the following nuclear reactions will generate an isotope?
(A) Neutron particle emission
(B) Positron emission
(C) α-particle emission
(D) β-particle emission
Answer:
(A) Neutron particle emission

Question 42.
Identify the nuclear reaction that differs from the rest-
(A) positron emission
(B) K-capture
(C) β-decay
(D) γ-decay
Answer:
(D) γ-decay

Question 43.
What is the order of reaction of the decay of ²³5{ _{92 U ?
(A) Zero
(B) first
(C) second
(D) third
Answer:
(B) first

Question 44.
Which of the following has maximum n / P ratio ?
(A) \({ }^{16} \mathrm{Ne}\)
(B) \({ }^{16} \mathrm{O}\)
(C) \({ }^{16} \mathrm{F}\)
(D) \({ }^{16} \mathrm{N}\)
Answer:
(D) \({ }^{16} \mathrm{N}\)

Question 45.
The half life of a radio isotope depends upon-
(A) the amount of isotope
(B) the temperature
(C) the pressure
(D) none of the above
Answer:
(D) none of the above

Question 46.
Which of the following has magic number of protons and neutrons?
(A) \({ }_8^{17} \mathrm{O}\)
(B) \({ }_13^{27} \mathrm{Al}\)
(C) \({ }_9^{17} \mathrm{Al}\)
(D) \({ }_40^{40} \mathrm{Al}\)
Answer:
(D) \({ }_40^{40} \mathrm{Al}\)

Question 47.
India conducted an underground nuclear test at-
(A) Tarapur
(B) Narora
(C) Pokhran
(D) Pushkar
Answer:
(D) Pokhran

Question 48.
Positron has mass equal to –
(A) eletron
(B) α-particle
(C) proton
(D) deutron
Answer:
(A) elecron

Question 49.
\({ }_1^1 \mathrm{H}\) + \({ }_1^3 \mathrm{H}\) (B) \({ }_2^4 \mathrm{He}\) represents –
(A) β-decay
(B) fusion
(C) fission
(D) d-decay
Answer:
(B) fusion

Question 50.
Choose the element which is not radioactive-
(A) Cm
(B) No
(C) Mo
(D) Md
Answer:
(C) Mo

Question 51.
Who discovered radioactivity :
(A) Bacquerel
(B) Madam curie
(c) Peary curie
(D) Ruther ford
Answer:
(A) Bacquerel

Question 52.
Which of the following rays has higher penetrating power ?
(A) sun ray
(B) β-ray
(c) α-ray
(D) γ-ray
Answer:
(D) γ-ray

Question 53.
Which ray is negatively charged ?
(A) α-ray
(B) β-ray
(C) γ-ray
(D) x-ray
Answer:
(B) β-ray

Question 54.
Due to emission of a β-particle the mass of the daughter element :
(A) Increased by one unit
(B) Decreased by one unit
(C) Remains the same
(D) Decreased by two unit
Answer:
(C) Remains the same

Question 55.
Binding energy is :
(A) Bonding between two atoms
(B) Fission of a covalent bond
(C) Binding among the nucleons in nucleus
(D) None of these
Answer:
(C) Binding among the nucleons in nucleus

Question 56.
Nuclear fission is initiated by :
(A) slow neutron
(B) fast neutron
(C) by proton
(D) by α-particle
Answer:
(A) slow neutron

Question 57.
Nuclear energy is :
(A) renewable
(B) not renewable
(C) sometime renewable
(D) it is a matter of debate
Answer:
(B) not renewable

Question 58.
The radioactive isotope used in atom bomb is :
(A) Ra-226
(B) U-238
(C) C-14
(D) U-235
Answer:
(D) U-235

Question 59.
Source of energy of sun is :
(A) Fission reaction
(B) Fusion reaction
(C) Spalation reaction
(D) None of these
Answer:
(B) Fusion reaction

Question 60.
Which nuclear decay emission consists of energy only?
(A) alpha particle
(B) beta particle
(C) gamma radiation
(D) positron emission
Answer:
(C) gamma radiation

Question 61.
Which of the following is the correct order of ionising power for α β, and γ ravs?
(A) α > β > γ
(B) α > γ > β
(C) γ > β > α
(D) β > α > γ
Answer:
(A) α > β > γ

Question 62.
Electromagnetic wave among the radloactive rays is :
(A) α-rays
(B) β-rays
(C) γ-rays
(D) cathode rays
Answer:
(c) γ-rays

Question 63.
Which one among the following nuclet has the lowest n:p ratio?
(A) Hydrogen
(B) Deuterium
(C) Tritium
(D) Helium
Answer:
(A) Hydrogen

Question 64.
Number of neutrons in a α-particle is :
(A) 1
(B) 2
(C) 3
(D) 4
Answer:
(B) 2

Question 65.
Identify the wrong statement :
(A) Radioactivity is a nuclear phenomena
(B) Emission of radioactive rays depends on the number of valence electrons
(C) Radioactivity was first discovered by Becquerel
(D) Three types of radiations are emitted during radiation from a radioactive element.
Answer:
(B) Emission of radioactive rays depends on the number of valence electrons.

Question 66.
Atom bomb was first used in war during
(A) World war II
(B) Gulf war
(C) Cuban war
(D) Indo-Pak war in 1965
Answer:
(A) World war II

Question 67.
Nuclear fission is initiated by :
(A) slow neutron
(B) proton
(C) fast neutron
(D) α particle
Answer:
(A) slow neutron

Question 68.
At around what mass number is the binding energy per nucleon greatest?
(A) 26
(B) 58
(C) 111
(D) 235
Answer:
(B) 58

Question 69.
The nuclear reaction \({ }_1^2 \mathrm{H}\) + \({ }_1^2 \mathrm{H}\) → \({ }_2^4 \mathrm{He}\) is called :
(A) fission reaction
(B) fusion reaction
(C) chain reaction
(D) thermal reaction
Answer:
(B) fusion reaction

Fill in the blanks :

1. Due to the large mass, a-particles possess large ______.
Answer:
Kinetic energy.

2. β-particles are _______ charged.
Answer:
negatively

3. γ-rays are _______.
Answer:
neutral

4. γ-rays have least effect on _______.
Answer:
photographic plates

5. Isotopes of the same element possess same number of _____.
Answer:
protons

6. Accroding to Einstein’s equation, the relationship between mass and energy can be written as ______.
Answer:
E = m c²

7. Atoms of the same element having same atomic number but different atomic masses are called ______.
Answer:
isotopes

8. Atoms of the different elements paossessing same mass number are called _____.
Answer:
Isobars.

9. Isotones are the nuclides having same number of ______.
Answer:
neutrons.

10. Atoms of the same element possessing identical atomic mass but differing in half-life period are called ______.
Answer:
nuclear isomers.

11. The phenomenon of spontaneous emission of invisible radiation is called ______
Answer:
radioactivity

12. β-particles are nothing but ______ moving with high speeds.
Answer:
electrons

13. Electrically neutral electromagnetic waves ejected during radioactive disintegration are called ______.
Answer:
γ-rays.

14. The phenomenon in which a stable nuclide is converted artificially into a radioactive substance is called _____.
Answer:
artificial radioactivity.

15. The speed of γ-rays is ______ speed of light.
Answer:
equal to

16. Atom bomb is based on nuclear _______ reaction.
Answer:
fission

17. Hydrogen bomb is based on nuclear _______ reaction.
Answer:
fusion

18. Source of the energy of the Sun is ______.
Answer:
fusion

19. The time taken for decay of half the initial amount of a radioactive nuclide is called _____.
Answer:
half-life period.

20. The energy required to separate a nucleus into its individual nucleons is known as _______.
Answer:
binding energy

21. The number of neutrons in a radioactive isotope of hydrogen is _____.
Answer:
2

22. The rate of disintegration of active nucleus is known as ______.
Answer:activity

23. \({ }_1^2 \mathrm{H}+{ }_1^3 \mathrm{H} \rightarrow{ }_2^4 \mathrm{He}\) is a _____ reaction.
Answer:
fusion

24. The mass defect in the formation of boron atom \(\frac{1}{5}\) B is 0.0810 amu. The binding energy per nucleon is ______.
Answer:
6.86 MeV

25. \({ }_7^{14} \mathrm{~N}+{ }_0^1 \mathrm{n}\) → ________ + \({ }_7^{14} \mathrm{H}\)
Answer:
{ _6^{-14 C

26. A radioactive nucleus decay emitting one α and two β particles, the daughter nucleus is _______ of the parent.
Answer:
isotope.

27. Particles having energy of several hundred MeV are known as _______.
Answer:
Superfast particles

28. An element \({ }_{\mathbf{Z}}^{\mathbf{A}} \mathbf{M}\) undergoes α-emission followed by two successive β-emissions. The element formed is _______.
Answer:
\(\mathrm{A}_z^{-4} \mathrm{M}\)

29. The end products in the natural disintegration series are stable isotopes of _____.
Answer:
lead

30. One curie of activity is equal to _______ disintegrations per second.
Answer:
3.7 × 10¹⁰

31. The energy equivalent to 1 amu is ______ MeV.
Answer:
931.5

32. The density of the nucleus is of the order of ______ g/cm³.
Answer:
10¹⁴

33. The difference between the total mass of the particles present in the nucleus of a nuclide and its real mass is called ______.
Answer:
mass defect

34. In exoergic reaction, the total mass of the products is _______ than the total mass of the reactants.
Answer:
less.

35. _______ is the inventor of neutron.
Answer:
J. Chadwick.

36. N₂O and CO₂ are the examples of ________.
Answer:
isosters

37. Magic numbers are 2, 8, 20, 50, 82 and ______.
Answer:
126

38. Radioactivity was proposed by ______.
Answer:
Madam curie.

39. Measurement of radioactivity is done by ______.
Answer:
Geiger-Muller counter.

40. The process of transforming one element into other is known as _______.
Answer:
alchemy.

41. Radioactivity was discovered by _______.
Answer:
Becquerel

42. Charge of an α-particle is _______.
Answer:
+2

43. β – particles are emitted from the _______ of the atom.
Answer:
nucleus.

44. \({ }^{60} \mathrm{C}_0\) isotope is used for the treatment of ______.
Answer:
cancer

45. \({ }^{226}{ }_{8 R} R a\) is a _______ element.
Answer:
radioactive

46. Bombardment of one U-235 with one neutron producer ______ neutrons.
Answer:
3

47. chernobyl located in _______.
Answer:
ukraine

48. One gram U-235 generates ________ kW/h electric energy.
Answer:
20,000

49. Fusion reaction occurs at _______ temperature.
Answer:
10⁶ K.

50. The inert gas present in each series is ________.
Answer:
Radon

51. The first radioactive element discovered was __________.
Answer:
uranium

52. In transformation series, radioactivity finally ceases with a a stable __________ isotope as the end product.
Answer:
lead

53. __________ is preceded by a fission reaction.
Answer:
Fusion

54. In a nuclear reactor, the part which consists of the moderator and fuel rods is known as _________.
Answer:
reactor core

55. ‘Atom bomb’ utilizes the ___________ reaction.
Answer:
fission

56. According to theory of relativity, mass can be converted to __________ and vice versa.
Answer:
energy

57. Natural uranium with extra U-235 added into it is called ___________.
Answer:
enriched uranium

58. The name of the aeroplane which dropped atom bomb on Hiroshima is ___________.
Answer:
Enola Gay

Q59. On an average ____________ neutrons are produced per each fission.
Answer:
2.5

State whether the following statement is True or False : VSA

1. Radioactivity depends on the number of electrons in the valence shell.
Answer:
False

2. The instability of nucleus in radioactive atoms is caused by the ratio of neutrons and protons in the nucleus.
Answer:
True

3. Radioactivity is a nuclear phenomena.
Answer:
True

4. Due to emission of a beta particle, mass number of the daughter element is decreased by 1 unit.
Answer:
False

5. When metallic radium is converted to radium chloride, it shows a change in the property of radioactivity.
Answer:
False

6. Radioactive tracer technique is used by researchers and medical practitioners.
Answer:
True

7. Fusion is basically just opposite to fission.
Answer:
True

8. Binding energy owes its origin to mass defect.
Answer:
True

9. Fission reaction releases a large amount of energy.
Answer:
True

10. Inside the thermal reactor, the control rods slow down the neutrons to stimulate further fission.
Answer:
False

11. Nuclear reactor is used to safely convert nuclear energy into electricity.
Answer:
True

12. Atom bomb is based on principles of thermonuclear fusion.
Answer:
False

13. Energy of the stars is attributed to nuclear fission reactions.
Answer:
False

14. The nuclear disaster in Fukushima was initiated after a Tsunami.
Answer:
True