Nuclear Chemistry Nuclear Chemistry

1. Who discovered radioactivity?

2. Who discovered radioactive elements radium (Ra) and polonium (Po)?

3. In which year did Henri Becquerel and Madam Curie jointly receive the Nobel Prize in Physics for radioactivity?

4. Which of the following statements is/are correct?

1. Radioactivity is a nuclear phenomenon.
2. Chemical changes have no role in radioactivity.
3. Radioactivity is a natural phenomenon and not caused by external factors.
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5. What is the criterion for the stability of a nucleus?

6. What kind of particles are emitted by radioactive substances?

7. Who discovered artificial radioactivity?

8. Which of the following elements exhibit artificial radioactivity?

9. How can a radioactive element be converted into a non-radioactive one?

10. Which of the following is not a radioactive element?

11. What is an α-particle?

12. The velocity of alpha particles is—

13. What is the alpha (α) ray?

15. Consider the following statements:

1. Alpha particles have more penetrating power than β and γ rays.
2. γ-rays have more ionizing power than α and β particles.

Which of the above is/are correct?

16. By the emission of an α-particle from a radioactive atom, the newly formed atom occupies a position in the periodic table—

Q17. The mass of an α-particle is equal to—

Q18. Which of the following has the minimum penetrating power?

Q19. Which of the following has the maximum ionizing power?

Q20. On emission of one alpha particle from a radioactive element, what changes occur in atomic number and mass number?

Q21. The charge present on an alpha particle is

Q22. Who first discovered the invisible rays emitted from a radioactive element?

Q23. Who discovered alpha and beta rays?

Q24. Who first detected gamma rays?

Q25. Radioactive substances do not emit—

Q26. In radioactive disintegration—

Q27. Which of the following has properties similar to an electron?

Q28. What charge is present on β-rays?

Q29. On emission of a β-particle, the newly formed atom—

Q30. Consider the following pairs—

1. Alpha : Positive charge
2. Beta : Negative charge
3. Gamma : Neutral (no charge)

Which of the above pairs is/are correct?

Q31. The β-particles emitted from a radioactive element are—

Q32. Radioactivity is a property of—

Q33. Gamma rays are made up of—

Q34. On emission of one β-particle, what is produced?

Q35. Gamma rays are—

Q36. After γ-ray emission from a radioactive element—

Q37. Which of the following has the maximum penetrating power?

Q38. Among the following, which has the minimum ionizing energy?

39. Statement A: Among α, β, and γ rays, the ionizing power of α-particles is the greatest.
       Statement R: Compared to β and γ rays, the α-particle is heavier.

Choose the correct option:

Q40. The penetrating power of β-rays is greater than that of α-particles of the same energy. Why?

Q41. According to the law of radioactive decay—

Q42. After decay, all radioactive elements ultimately transform into—

Q43. Which of the following is not a radioactive element?

Q44. The most powerful radioactive element is—

47.If a radioactive element emits one α-particle and two β-particles, then the resulting atom will be—

52.Radioactive substances should be kept in a container made of—

53.On emission of a β-particle, the nucleus's neutron-to-proton ratio (n/p ratio)—

54.Which of the following elements does not show natural radioactivity?

55. Consider the following statements:

1. Radioactivity was first discovered by Henri Becquerel.
2. The term ‘radioactivity’ was used for the first time by Madame Curie.

Which of the above statements is/are correct?

Q.56. Radioactivity is measured by—

Q.57. The unit of radioactivity is—

58. The SI unit of radioactivity is—

Q.59. The amount of a substance that gives 3.7×107 disintegrations per second (dps) is—

Q.60. If the quantity of a radioactive substance is doubled, then the rate of radioactive decay will—

Q.61. A radioactive substance has a half-life of 4 months.
In how much time will three-fourths of this substance decay?

63. The half-life of a radioactive substance is 70 days. If the initial amount is 1 gram, after how many days will only 0.25 gram remain?

"The quantity of a radioactive element is found to be one-sixteenth of its original amount after 2 hours. The half-life of the element will be—"

If the half-life of a radioactive substance is 1 day, then after 4 days what fraction of its initial amount will remain?

Options:

Q.67. The age of the Earth is estimated by—

Q.68. Which method is used to determine the age of very ancient rocks?

Q.69. The radioactive method used to determine the age of prehistoric materials is called—

Q.70. The half-life of a radioactive element depends on its initial concentration—

Q.72. The reaction in which light nuclei combine to form a heavier nucleus is called—

Q.71. The reaction in which a large nucleus splits into smaller nuclei is called—

Q.73. In nuclear reactions (fusion and fission), a huge amount of energy is released. Why?

Q.74. The equivalent energy of 1 amu of mass is—

Q.76. During nuclear fission—

Q.77. Consider the following statements:

1. The law of mass conservation is not obeyed in a nuclear reaction.
2. The law of energy conservation is not obeyed in a nuclear reaction.

Which of the above statements is/are correct?

78. In a nuclear reaction, the conserved physical quantity is—

Q.79. The source of energy of the Sun and other stars is—

80. Who first discovered that the energy obtained from the Sun is the result of nuclear fusion?

Q.81. In which nuclear reaction is the most harmful radiation produced?

82. Which of the following nuclear reactions is a chain reaction?

Q.83. An atomic bomb is based on which principle?

84. The hydrogen bomb is based on which principle?

Q.85. Why is nuclear fusion called a thermonuclear reaction?

86. Who developed the hydrogen bomb?

Q.87. Consider the following statements:

1. In nuclear bombs, a chain reaction is used to produce an enormous amount of energy, but in a nuclear reactor, no chain reaction occurs.
2. In nuclear bombs, the reaction is uncontrolled, whereas in a reactor, the reaction is controlled.

Which of the above statements is/are correct?

Q.88. Who invented the atomic bomb?

89. Consider the following statements:

1. The same amount of energy is released in both fusion and fission.
2. In fusion, the energy released per unit mass is greater than that in fission.

Which of the above is/are correct?

Q.90. The working principle of a nuclear reactor is based on—

91. Which particle is required to sustain the continuous process of uranium fission?

Q.92. Which of the following minerals is used as fuel in an atomic energy plant (nuclear reactor)?

93. Which fuel is generally used in a nuclear power station (nuclear reactor) to produce heat?

Q.94. In a nuclear reactor, the function of a moderator is—

95. Consider the following statements regarding a nuclear reactor:

1. The function of the moderator is to slow down the neutrons.
2. The function of the control rods is to absorb neutrons.

Which of the above statements is/are correct?

Q.96. The phenomenon in which atomic nuclei combine to form a new nucleus and release energy is called—

97. In a nuclear reactor, which of the following is used as a moderator?

Q.98. For the construction of a nuclear reactor, which of the following elements is required?

Q.99. Which of the following acts as a coolant in a nuclear reactor?

Q.101. In a nuclear reactor, which substance is used both as a moderator and as a coolant?

Q.100. Consider the following statements:

1. Radioactivity cannot be controlled by any external factors.
2. Nuclear fission can be controlled using external devices.

Which of the above statements is/are correct?

102. In a nuclear reactor, what is used as a neutron controller?

Q.103. What is a nuclear reactor?

Q.105. Beta (β) particles are deflected in—

104. The difference between a nuclear reactor and an atomic bomb is—

106. Where is atomic fuel used?

Q.107. In atomic and hydrogen bomb explosions, a huge amount of energy is released due to—

Q.108. Consider the following statements:

1. Atomic bomb is based on controlled nuclear fusion.
2. Hydrogen bomb is based on uncontrolled nuclear fission.

Which of the above statements is/are correct?

Q.109. Consider the following statements:

Statement (A): Rutherford said before the Royal Society that nuclear power would never be available to humans.
Reason (R): He believed that Einstein’s equation would fail and mass could not be converted into energy.

Codes:

Q.110. The source of inexhaustible energy in stars is—