1. Which isotope of hydrogen is the most stable and abundant?
- a) Protium
- b) Deuterium
- c) Tritium
- d) All are equally abundant
Answer: a) Protium
Explanation:
Protium is the most stable and abundant isotope of hydrogen, constituting over 99.98% of the hydrogen found in nature. Deuterium is much less abundant, and tritium is rare and radioactive.
2. The nucleus of deuterium is also known as:
- a) Deutron
- b) Proton
- c) Triton
- d) Neutron
Answer: a) Deutron
Explanation:
The nucleus of deuterium, consisting of one proton and one neutron, is called a deuteron. Protium’s nucleus is just a proton, and triton refers to the nucleus of tritium.
3. Tritium undergoes which type of radioactive decay?
- a) Alpha decay
- b) Beta decay
- c) Gamma decay
- d) None of these
Answer: b) Beta decay
Explanation:
Tritium decays by beta decay, where a neutron is converted into a proton, releasing an electron (beta particle) and an antineutrino.
4. Which isotope of hydrogen is used in heavy water (D₂O)?
- a) Protium
- b) Deuterium
- c) Tritium
- d) None of these
Answer: b) Deuterium
Explanation:
Heavy water (D₂O) is water in which the protium (H) atoms are replaced with deuterium (D), which is an isotope of hydrogen that contains one neutron.
5. The half-life of tritium is approximately:
- a) 5 years
- b) 10 years
- c) 12.3 years
- d) 20 years
Answer: c) 12.3 years
Explanation:
Tritium has a half-life of about 12.3 years, after which half of a given sample of tritium will have decayed into helium-3 through beta decay.
6. Which isotope of hydrogen is commonly used as a tracer in biochemical studies?
- a) Protium
- b) Deuterium
- c) Tritium
- d) None of these
Answer: c) Tritium
Explanation:
Tritium, due to its radioactive properties, is used as a tracer in biochemical and medical studies, allowing researchers to track the movement of hydrogen atoms in biological systems.
7. The presence of deuterium in water makes it:
- a) Less dense than normal water
- b) More dense than normal water
- c) Lighter than normal water
- d) No effect on density
Answer: b) More dense than normal water
Explanation:
Heavy water (D₂O) is denser than regular water (H₂O) because deuterium atoms are heavier than protium atoms due to the presence of a neutron in the nucleus.
What is the chemical symbol for heavy water?
- a) H₂O
- b) D₂O
- c) T₂O
- d) H₃O
Answer: b) D₂O
Explanation:
Heavy water is composed of two deuterium atoms and one oxygen atom, and its chemical formula is D₂O. It is used in nuclear reactors as a neutron moderator.
Which of the following isotopes of hydrogen is used in hydrogen bombs?
- a) Protium
- b) Deuterium
- c) Tritium
- d) Both b and c
Answer: d) Both b and c
Explanation:
Both deuterium and tritium are used in hydrogen bombs to fuel nuclear fusion reactions, which release a large amount of energy. Protium is not used in such reactions.
8. The nucleus of deuterium is also known as:
- a) Deutron
- b) Proton
- c) Neutron
- d) Triton
Answer: a) Deutron
Explanation:
The nucleus of deuterium, consisting of one proton and one neutron, is called a deuteron. A proton is the nucleus of protium, and a triton is the nucleus of tritium.
9. Tritium undergoes which type of radioactive decay?
- a) Alpha decay
- b) Beta decay
- c) Gamma decay
- d) Neutron emission
Answer: b) Beta decay
Explanation:
Tritium undergoes beta decay, where a neutron in its nucleus is converted into a proton, and an electron (beta particle) is emitted. This transforms tritium into helium-3.
10. Which isotope of hydrogen is used in heavy water (D₂O)?
- a) Protium
- b) Deuterium
- c) Tritium
- d) None of these
Answer: b) Deuterium
Explanation:
Heavy water (D₂O) contains deuterium, the isotope of hydrogen with one proton and one neutron. It is used in nuclear reactors as a neutron moderator.
11. Which of the following correctly represents the isotopic composition of hydrogen?
- a) ¹H, ²H, ³H
- b) ¹H, ³He, ²He
- c) ¹H, ²He, ³He
- d) ¹H, ²H, ³He
Answer: a) ¹H, ²H, ³H
Explanation:
Hydrogen has three isotopes: protium (¹H), deuterium (²H), and tritium (³H). Each isotope has the same number of protons but different numbers of neutrons.
12. In which of the following forms can tritium be found?
- a) Naturally occurring in large quantities
- b) Produced in nuclear reactors
- c) A stable isotope of hydrogen
- d) As a component of natural gas
Answer: b) Produced in nuclear reactors
Explanation:
Tritium is a radioactive isotope of hydrogen that is produced artificially in nuclear reactors or during nuclear weapon tests. It is not found in large quantities in nature.
13. Which of the following isotopes of hydrogen is used as a tracer in biological experiments?
- a) Protium
- b) Deuterium
- c) Tritium
- d) None of these
Answer: c) Tritium
Explanation:
Tritium, being radioactive, is commonly used as a tracer in biological and chemical experiments to track the movement of molecules.
14. Which property of isotopes makes them chemically identical?
- a) Same mass number
- b) Same number of protons
- c) Same number of neutrons
- d) Same number of nucleons
Answer: b) Same number of protons
Explanation:
Isotopes of the same element have the same number of protons and electrons, giving them identical chemical properties. The difference lies in their number of neutrons, affecting their mass and nuclear properties.
15. Which of the following statements is true about tritium?
- a) It is stable.
- b) It has two neutrons.
- c) It has no neutrons.
- d) It is used in light water reactors.
Answer: b) It has two neutrons
Explanation:
Tritium (³H) has one proton and two neutrons in its nucleus. It is radioactive and decays via beta decay. Tritium is not stable, unlike protium and deuterium.
16. Deuterium is used in which type of fusion reaction?
- a) Proton-proton chain
- b) Deuterium-deuterium fusion
- c) Carbon-nitrogen cycle
- d) Helium burning
Answer: b) Deuterium-deuterium fusion
Explanation:
In deuterium-deuterium fusion, two deuterium nuclei fuse to form helium or tritium, releasing energy. This process occurs at extremely high temperatures and pressures, such as in stars.
17. What is the difference in the number of neutrons between protium and tritium?
- a) 1
- b) 2
- c) 3
- d) 4
Answer: b) 2
Explanation:
Protium (¹H) has no neutrons, while tritium (³H) has two neutrons. The difference in their neutron count is 2.
18. Which isotope of hydrogen has the highest atomic mass?
- a) Protium
- b) Deuterium
- c) Tritium
- d) All isotopes have the same atomic mass
Answer: c) Tritium
Explanation:
Tritium has the highest atomic mass (³H) because it has two neutrons in addition to one proton, making it heavier than both protium (¹H) and deuterium (²H).
19. Which isotope of hydrogen is most commonly found in nature?
- a) Protium
- b) Deuterium
- c) Tritium
- d) Equal amounts of all
Answer: a) Protium
Explanation:
Protium (¹H) is the most common isotope of hydrogen, making up more than 99.98% of hydrogen found in nature.
20. Which of the following isotopes is used in nuclear reactors to moderate neutrons?
- a) Protium
- b) Deuterium
- c) Tritium
- d) Helium
Answer: b) Deuterium
Explanation:
Deuterium, in the form of heavy water (D₂O), is used in nuclear reactors as a neutron moderator to slow down fast neutrons and maintain the chain reaction.
21. Which of the following describes the main difference between isotopes of hydrogen?
- a) The number of protons
- b) The number of neutrons
- c) The number of electrons
- d) The number of energy levels
Answer: b) The number of neutrons
Explanation:
The difference between isotopes of hydrogen lies in the number of neutrons in their nuclei. Protium has no neutrons, deuterium has one neutron, and tritium has two neutrons.
22. Which of the following isotopes is stable?
- a) Protium
- b) Deuterium
- c) Both protium and deuterium
- d) Tritium
Answer: c) Both protium and deuterium
Explanation:
Both protium (¹H) and deuterium (²H) are stable isotopes of hydrogen. Tritium (³H) is radioactive and undergoes beta decay.
23. Which of the following isotopes of hydrogen is radioactive?
- a) Protium
- b) Deuterium
- c) Tritium
- d) None of these
Answer: c) Tritium
Explanation:
Tritium is radioactive and decays by emitting a beta particle. Protium and deuterium are stable isotopes.
24. In which of the following processes is deuterium commonly used?
- a) Beta decay
- b) Nuclear fission
- c) Nuclear fusion
- d) Radioactive decay
Answer: c) Nuclear fusion
Explanation:
Deuterium is often used in nuclear fusion reactions, such as in experimental fusion reactors, to produce helium and release large amounts of energy.
25. Which isotope of hydrogen is most commonly used in nuclear weapons?
- a) Protium
- b) Deuterium
- c) Tritium
- d) None of these
Answer: c) Tritium
Explanation:
Tritium is used in thermonuclear (hydrogen) bombs to enhance the fusion reaction, often in combination with deuterium.
26. Which of the following best describes heavy water?
- a) Water with extra hydrogen atoms
- b) Water containing deuterium instead of protium
- c) Water containing tritium
- d) Water with added neutrons
Answer: b) Water containing deuterium instead of protium
Explanation:
Heavy water (D₂O) contains deuterium, the isotope of hydrogen with one proton and one neutron, in place of protium (ordinary hydrogen).
27. Which property of isotopes changes due to a difference in the number of neutrons?
- a) Chemical properties
- b) Physical properties
- c) Atomic number
- d) Charge
Answer: b) Physical properties
Explanation:
Isotopes have different physical properties due to the difference in their mass (caused by the different number of neutrons). Their chemical properties remain almost identical because they have the same number of protons and electrons.
28. Tritium is used in which of the following applications?
- a) Fuel for internal combustion engines
- b) Radioactive tracers in biological experiments
- c) Manufacturing glass
- d) Solar panels
Answer: b) Radioactive tracers in biological experiments
Explanation:
Tritium is used as a radioactive tracer in biological and chemical research due to its ability to emit beta radiation, which can be tracked in various processes.
29. Which of the following isotopes of hydrogen is the lightest?
- a) Protium
- b) Deuterium
- c) Tritium
- d) They all have the same mass
Answer: a) Protium
Explanation:
Protium (¹H) is the lightest isotope of hydrogen because it has no neutrons. Deuterium (²H) has one neutron, and tritium (³H) has two neutrons, making them heavier.
30. Which isotope of hydrogen is found in nature in the smallest amount?
- a) Protium
- b) Deuterium
- c) Tritium
- d) All are found in equal amounts
Answer: c) Tritium
Explanation:
Tritium is extremely rare in nature and is mostly produced artificially in nuclear reactions. Protium is the most abundant, followed by deuterium.
31. Which of the following describes the emission in tritium decay?
- a) Alpha particle
- b) Beta particle
- c) Gamma ray
- d) Neutron
Answer: b) Beta particle
Explanation:
Tritium decays by emitting a beta particle (an electron), converting one of its neutrons into a proton, which changes tritium into helium-3.
32. Which isotope of hydrogen has an atomic mass of approximately 2 amu?
- a) Protium
- b) Deuterium
- c) Tritium
- d) None of these
Answer: b) Deuterium
Explanation:
Deuterium has an atomic mass of about 2 atomic mass units (amu) because its nucleus contains one proton and one neutron, each contributing approximately 1 amu.
33. What is the symbol for tritium?
- a) ²H
- b) ³H
- c) ⁴H
- d) T
Answer: b) ³H
Explanation:
Tritium is represented by the symbol ³H, indicating it has one proton and two neutrons in its nucleus. Sometimes, tritium is also denoted as “T” in casual references.
34. Which isotope of hydrogen is used in luminous paints for self-powered lighting?
- a) Protium
- b) Deuterium
- c) Tritium
- d) All of these
Answer: c) Tritium
Explanation:
Tritium is used in luminous paints, such as those used in watch dials, as it emits low-energy beta particles that interact with phosphors to produce light.
35. How many neutrons are present in deuterium?
- a) 0
- b) 1
- c) 2
- d) 3
Answer: b) 1
Explanation:
Deuterium (²H) has one neutron in its nucleus, in addition to one proton.
36. Which isotope of hydrogen has the longest half-life?
- a) Protium
- b) Deuterium
- c) Tritium
- d) They all have the same half-life
Answer: c) Tritium
Explanation:
Tritium has a half-life of about 12.32 years. Protium and deuterium are stable isotopes and do not undergo radioactive decay, so they do not have half-lives.
37. Which isotope of hydrogen is most suitable for studying isotopic effects in chemical reactions?
- a) Protium
- b) Deuterium
- c) Tritium
- d) Helium
Answer: b) Deuterium
Explanation:
Deuterium is often used in studies of isotopic effects because its mass is about twice that of protium, leading to observable differences in reaction rates and other properties in chemical reactions.
38. Which isotope of hydrogen is used in thermonuclear reactions?
- a) Protium
- b) Deuterium
- c) Tritium
- d) Both b and c
Answer: d) Both b and c
Explanation:
Both deuterium and tritium are used in thermonuclear (fusion) reactions, where their nuclei fuse at high temperatures to form helium and release energy.
39. In the laboratory, tritium can be produced by bombarding lithium with:
- a) Alpha particles
- b) Protons
- c) Neutrons
- d) Electrons
Answer: c) Neutrons
Explanation:
Tritium is produced in nuclear reactors by bombarding lithium-6 with neutrons, which results in the formation of tritium and helium-4.
40. Which isotope of hydrogen is also called hydrogen-1?
- a) Protium
- b) Deuterium
- c) Tritium
- d) None of these
Answer: a) Protium
Explanation:
Protium is also known as hydrogen-1 because it has a mass number of 1, consisting of one proton and no neutrons.
41. Which of the following isotopes of hydrogen is often used in chemical reaction studies to observe kinetic isotope effects?
- a) Protium
- b) Deuterium
- c) Tritium
- d) None of these
Answer: b) Deuterium
Explanation:
Deuterium is used in chemical studies to observe kinetic isotope effects because its heavier mass compared to protium leads to measurable differences in reaction rates.
42. Which of the following isotopes of hydrogen is the heaviest?
- a) Protium
- b) Deuterium
- c) Tritium
- d) None of these
Answer: c) Tritium
Explanation:
Tritium is the heaviest isotope of hydrogen, with one proton and two neutrons, giving it a mass of approximately 3 atomic mass units (amu).
43. Tritium is primarily used in:
- a) Fossil fuel combustion
- b) Radioactive tracers and thermonuclear reactions
- c) Solar power generation
- d) Photosynthesis experiments
Answer: b) Radioactive tracers and thermonuclear reactions
Explanation:
Tritium is used in biological research as a radioactive tracer and also in thermonuclear reactions due to its ability to release large amounts of energy upon fusion.
44. Which isotope of hydrogen is used to make heavy water?
- a) Protium
- b) Deuterium
- c) Tritium
- d) Helium
Answer: b) Deuterium
Explanation:
Heavy water (D₂O) contains deuterium instead of protium. It is used in certain types of nuclear reactors as a moderator.
45. Which of the following isotopes of hydrogen can be used for energy production through fusion?
- a) Protium
- b) Deuterium
- c) Tritium
- d) Both b and c
Answer: d) Both b and c
Explanation:
Both deuterium and tritium are used in fusion reactions, where they combine at extremely high temperatures to form helium, releasing a large amount of energy.
46. Which isotope of hydrogen is produced in nuclear reactors and used in hydrogen bombs?
- a) Protium
- b) Deuterium
- c) Tritium
- d) None of these
Answer: c) Tritium
Explanation:
Tritium is produced in nuclear reactors and used in hydrogen bombs to enhance the fusion reaction and boost explosive power.
47. What is the approximate half-life of tritium?
- a) 10 years
- b) 12.32 years
- c) 15 years
- d) 20 years
Answer: b) 12.32 years
Explanation:
Tritium has a half-life of approximately 12.32 years. It decays via beta emission into helium-3.
48. Which of the following is true about deuterium oxide (D₂O)?
- a) It is lighter than normal water.
- b) It has different physical properties from normal water.
- c) It is highly reactive with normal water.
- d) It has the same physical and chemical properties as normal water.
Answer: b) It has different physical properties from normal water.
Explanation:
Deuterium oxide (D₂O), or heavy water, has a higher density and boiling point compared to normal water (H₂O) because deuterium is heavier than protium.
49. Which isotope of hydrogen is present in the lowest abundance on Earth?
- a) Protium
- b) Deuterium
- c) Tritium
- d) None of these
Answer: c) Tritium
Explanation:
Tritium is extremely rare in nature, occurring in very small amounts. Protium is the most abundant, followed by deuterium.
50. Which of the following reactions is used to produce tritium?
- a) Lithium-6 neutron bombardment
- b) Carbon-12 fusion
- c) Proton-proton chain
- d) Electron capture by deuterium
Answer: a) Lithium-6 neutron bombardment
Explanation:
Tritium is produced by bombarding lithium-6 with neutrons, which results in the formation of tritium and helium-4.
51. Which of the following isotopes of hydrogen is used in nuclear fusion research?
- a) Protium
- b) Deuterium
- c) Tritium
- d) Both b and c
Answer: d) Both b and c
Explanation:
Both deuterium and tritium are used in nuclear fusion research because their nuclei can fuse at high temperatures, releasing significant energy.
52. The energy released in a hydrogen bomb is primarily due to:
- a) Fission of uranium
- b) Fusion of deuterium and tritium
- c) Combustion of hydrogen gas
- d) Electromagnetic radiation
Answer: b) Fusion of deuterium and tritium
Explanation:
The immense energy released in a hydrogen bomb comes from the fusion of deuterium and tritium nuclei, producing helium and energy.
53. Which of the following is not a property of deuterium?
- a) It is stable.
- b) It has one neutron.
- c) It is radioactive.
- d) It can be used to produce heavy water.
Answer: c) It is radioactive.
Explanation:
Deuterium is a stable isotope of hydrogen. It is not radioactive, unlike tritium.
54. Which isotope of hydrogen is used to trace the flow of water in environmental studies?
- a) Protium
- b) Deuterium
- c) Tritium
- d) None of these
Answer: c) Tritium
Explanation:
Tritium is used as a tracer to track water movement in hydrological and environmental studies due to its radioactive properties.
55. Which of the following processes does not involve the use of deuterium?
- a) Nuclear fusion
- b) Neutron moderation in reactors
- c) Radioactive dating
- d) Chemical reaction studies
Answer: c) Radioactive dating
Explanation:
Deuterium is not used in radioactive dating. It is stable, unlike radioactive isotopes such as carbon-14, which are used for dating.
56. Which of the following elements is required to produce tritium in a nuclear reactor?
- a) Helium
- b) Lithium
- c) Hydrogen
- d) Carbon
Answer: b) Lithium
Explanation:
Tritium is produced in nuclear reactors by bombarding lithium-6 with neutrons, resulting in the formation of tritium and helium.
57. What is the main use of heavy water in nuclear reactors?
- a) Fuel
- b) Moderator
- c) Coolant
- d) Radiation shield
Answer: b) Moderator
Explanation:
Heavy water (D₂O) is used as a neutron moderator in nuclear reactors to slow down fast neutrons, allowing them to sustain the fission chain reaction.
58. Which of the following isotopes of hydrogen is naturally stable?
- a) Protium
- b) Deuterium
- c) Tritium
- d) Both a and b
Answer: d) Both a and b
Explanation:
Both protium and deuterium are stable isotopes of hydrogen. Tritium, on the other hand, is radioactive.
59. What is the most common isotope of hydrogen found in the universe?
- a) Protium
- b) Deuterium
- c) Tritium
- d) None of these
Answer: a) Protium
Explanation:
Protium (¹H), which has no neutrons, is by far the most abundant isotope of hydrogen in the universe, making up over 99.98% of hydrogen.
60. Which of the following statements about heavy water is correct?
- a) It contains tritium.
- b) It is used as a fuel in nuclear reactors.
- c) It is used as a moderator in some nuclear reactors.
- d) It contains helium.
Answer: c) It is used as a moderator in some nuclear reactors.
Explanation:
Heavy water (D₂O) contains deuterium and is used as a neutron moderator in some nuclear reactors, particularly in CANDU reactors.
61. Which of the following isotopes of hydrogen is the most suitable for use in hydrogen nuclear fusion reactors?
- a) Protium
- b) Deuterium
- c) Tritium
- d) Both b and c
Answer: d) Both b and c
Explanation:
Both deuterium and tritium are used in hydrogen fusion reactions due to their ability to fuse at high temperatures, releasing large amounts of energy.
62. Which of the following is true about the mass of deuterium compared to protium?
- a) Deuterium is twice as heavy as protium.
- b) Deuterium is the same mass as protium.
- c) Deuterium is lighter than protium.
- d) Deuterium is three times heavier than protium.
Answer: a) Deuterium is twice as heavy as protium.
Explanation:
Deuterium has one neutron in addition to the proton, making it about twice as heavy as protium, which has no neutrons.
63. Which isotope of hydrogen is used in nuclear fusion research because of its ability to easily undergo fusion at relatively low temperatures?
- a) Protium
- b) Deuterium
- c) Tritium
- d) Helium-3
Answer: c) Tritium
Explanation:
Tritium is used in nuclear fusion research because it fuses at relatively lower temperatures than other isotopes, making it ideal for fusion experiments.
64. What happens to the atomic number of tritium when it decays?
- a) It increases by 1
- b) It decreases by 1
- c) It remains the same
- d) It becomes zero
Answer: a) It increases by 1
Explanation:
Tritium undergoes beta decay, in which a neutron is converted into a proton, increasing the atomic number from 1 (hydrogen) to 2 (helium).
65. Which of the following is the correct chemical formula for heavy water?
- a) H₂O
- b) D₂O
- c) H₂T
- d) D₂T
Answer: b) D₂O
Explanation:
Heavy water is chemically represented as D₂O, where the hydrogen atoms in water are replaced with deuterium, a heavier isotope of hydrogen.
66. What is the primary difference between deuterium and tritium?
- a) The number of protons
- b) The number of neutrons
- c) The atomic number
- d) The number of electrons
Answer: b) The number of neutrons
Explanation:
Deuterium has one neutron, while tritium has two neutrons. Both have the same number of protons and electrons.
67. Which isotope of hydrogen has the highest neutron-to-proton ratio?
- a) Protium
- b) Deuterium
- c) Tritium
- d) All have the same ratio
Answer: c) Tritium
Explanation:
Tritium has the highest neutron-to-proton ratio (2 neutrons for 1 proton), while deuterium has 1 neutron per proton and protium has no neutrons.
68. Which isotope of hydrogen is most commonly found in water?
- a) Protium
- b) Deuterium
- c) Tritium
- d) All of these
Answer: a) Protium
Explanation:
Protium, the most abundant isotope of hydrogen, is the most commonly found hydrogen isotope in normal water (H₂O).
69. Which of the following isotopes of hydrogen is used in glow-in-the-dark watches and signs?
- a) Protium
- b) Deuterium
- c) Tritium
- d) None of these
Answer: c) Tritium
Explanation:
Tritium is used in luminous watches and signs because its beta radiation can cause phosphorescent materials to glow.
70. The process by which two nuclei combine to form a heavier nucleus, releasing energy, is called:
- a) Nuclear fission
- b) Nuclear fusion
- c) Radioactive decay
- d) Ionization
Answer: b) Nuclear fusion
Explanation:
In nuclear fusion, two light nuclei (such as deuterium and tritium) combine to form a heavier nucleus (such as helium), releasing large amounts of energy.
71. Which isotope of hydrogen is naturally radioactive?
- a) Protium
- b) Deuterium
- c) Tritium
- d) None of these
Answer: c) Tritium
Explanation:
Tritium is a naturally radioactive isotope of hydrogen, emitting beta particles as it decays into helium-3.
72. Heavy water is used as a moderator in nuclear reactors because:
- a) It absorbs neutrons
- b) It slows down fast neutrons
- c) It speeds up nuclear reactions
- d) It absorbs gamma rays
Answer: b) It slows down fast neutrons
Explanation:
Heavy water is used as a moderator in nuclear reactors to slow down fast neutrons, making them more likely to induce fission in nuclear fuel.
73. Which of the following isotopes of hydrogen is stable?
- a) Protium
- b) Deuterium
- c) Tritium
- d) Both a and b
Answer: d) Both a and b
Explanation:
Protium and deuterium are stable isotopes of hydrogen, while tritium is radioactive.
74. Which isotope of hydrogen is most commonly used in fusion reactors?
- a) Protium
- b) Deuterium
- c) Tritium
- d) None of these
Answer: b) Deuterium
Explanation:
Deuterium is commonly used in fusion reactors, often in combination with tritium, because it is easier to fuse than protium and is relatively abundant.
75. In tritium, how many neutrons are there in its nucleus?
- a) 0
- b) 1
- c) 2
- d) 3
Answer: c) 2
Explanation:
Tritium has one proton and two neutrons in its nucleus, making it the heaviest isotope of hydrogen.
76. Which of the following isotopes of hydrogen can be used to produce energy in a hydrogen bomb?
- a) Protium
- b) Deuterium
- c) Tritium
- d) Both b and c
Answer: d) Both b and c
Explanation:
Both deuterium and tritium are used in the fusion reactions that take place in hydrogen bombs, releasing a large amount of energy.
77. The neutron-to-proton ratio in deuterium is:
- a) 0
- b) 1
- c) 2
- d) 3
Answer: b) 1
Explanation:
Deuterium has one proton and one neutron, so its neutron-to-proton ratio is 1.
78. Which of the following best describes a deuteron?
- a) A hydrogen atom with no neutrons
- b) A nucleus of deuterium consisting of one proton and one neutron
- c) A nucleus of tritium consisting of one proton and two neutrons
- d) A helium atom with two neutrons
Answer: b) A nucleus of deuterium consisting of one proton and one neutron
Explanation:
A deuteron is the nucleus of a deuterium atom, containing one proton and one neutron.
79. Which isotope of hydrogen is used as a tracer in medical research?
- a) Protium
- b) Deuterium
- c) Tritium
- d) None of these
Answer: c) Tritium
Explanation:
Tritium is used as a radioactive tracer in medical research to study biological processes due to its ability to emit beta radiation.
80. Tritium is commonly produced in which type of nuclear reactor?
- a) Fast breeder reactors
- b) Pressurized water reactors
- c) Fusion reactors
- d) Heavy water reactors
Answer: d) Heavy water reactors
Explanation:
Tritium is commonly produced as a byproduct in heavy water reactors, where neutrons interact with deuterium or lithium to form tritium.
81. Which of the following is true about tritium’s radioactivity?
- a) It emits alpha particles.
- b) It emits gamma rays.
- c) It emits beta particles.
- d) It is not radioactive.
Answer: c) It emits beta particles.
Explanation:
Tritium is a radioactive isotope of hydrogen that decays by emitting low-energy beta particles. These beta particles are non-penetrating and pose little threat externally but can be harmful if ingested.
82. In which of the following applications is tritium most commonly used?
- a) Fluorescent lighting
- b) Thermonuclear weapons
- c) Food irradiation
- d) MRI machines
Answer: b) Thermonuclear weapons
Explanation:
Tritium is used in thermonuclear weapons to boost the explosive power by facilitating the fusion reaction. It is also used in small amounts for self-luminous devices, but its primary application is in nuclear weapons.
83. The presence of which isotope distinguishes heavy water from normal water?
- a) Protium
- b) Deuterium
- c) Tritium
- d) Oxygen-18
Answer: b) Deuterium
Explanation:
Heavy water (D₂O) contains deuterium, an isotope of hydrogen with one neutron, instead of protium, which is present in normal water (H₂O).
84. Which property of tritium makes it useful as a tracer in environmental studies?
- a) Its stability
- b) Its radioactivity
- c) Its high neutron count
- d) Its chemical reactivity
Answer: b) Its radioactivity
Explanation:
Tritium’s radioactivity allows it to be easily traced in environmental and hydrological studies. The beta radiation emitted by tritium can be detected, providing information about water movement and contamination.
85. Which isotope of hydrogen is used in the production of luminous paints for watches and instrument dials?
- a) Protium
- b) Deuterium
- c) Tritium
- d) None of these
Answer: c) Tritium
Explanation:
Tritium is used in self-luminous paints for watches and instrument dials. It reacts with phosphor to produce light without an external energy source.
86. What is the symbol for the isotope of hydrogen with two neutrons?
- a) ¹H
- b) ²H
- c) ³H
- d) None of these
Answer: c) ³H
Explanation:
The symbol for tritium, the isotope of hydrogen with two neutrons, is ³H. It consists of one proton and two neutrons.
87. Which isotope of hydrogen is the lightest?
- a) Protium
- b) Deuterium
- c) Tritium
- d) None of these
Answer: a) Protium
Explanation:
Protium is the lightest isotope of hydrogen. It has no neutrons, only one proton, giving it an atomic mass of about 1 amu.
88. In fusion reactions, the combination of deuterium and tritium results in the formation of:
- a) Helium and a neutron
- b) Carbon and oxygen
- c) Hydrogen and oxygen
- d) Lithium and hydrogen
Answer: a) Helium and a neutron
Explanation:
When deuterium and tritium undergo fusion, they form helium (He-4) and release a neutron along with a large amount of energy.
89. Which of the following isotopes is most commonly used in nuclear fusion research due to its abundance in nature?
- a) Protium
- b) Deuterium
- c) Tritium
- d) None of these
Answer: b) Deuterium
Explanation:
Deuterium is commonly used in nuclear fusion research because it is more abundant in nature than tritium and easier to obtain.
90. Which isotope of hydrogen is the least abundant in the universe?
- a) Protium
- b) Deuterium
- c) Tritium
- d) None of these
Answer: c) Tritium
Explanation:
Tritium is the least abundant isotope of hydrogen in the universe. It occurs naturally only in trace amounts due to cosmic ray interactions with the atmosphere.
91. What is the primary purpose of using deuterium in nuclear reactors?
- a) To generate electricity directly
- b) To act as a neutron moderator
- c) To absorb gamma radiation
- d) To produce heavy water
Answer: b) To act as a neutron moderator
Explanation:
Deuterium is used in nuclear reactors, typically in the form of heavy water, to slow down neutrons and sustain the nuclear fission chain reaction.
92. Which of the following isotopes of hydrogen is most suitable for use in long-term biological studies?
- a) Protium
- b) Deuterium
- c) Tritium
- d) Helium-3
Answer: b) Deuterium
Explanation:
Deuterium is used in biological studies as it is stable and does not pose the radioactive hazards associated with tritium. It is used to study metabolism and other biological processes.
93. Which of the following is true regarding tritium’s half-life?
- a) It is less than a year.
- b) It is approximately 12.3 years.
- c) It is more than 100 years.
- d) It does not decay.
Answer: b) It is approximately 12.3 years.
Explanation:
Tritium has a half-life of about 12.3 years, after which half of the tritium in a sample will have decayed into helium-3 through beta decay.
94. Which isotope of hydrogen is most abundant in the Sun?
- a) Protium
- b) Deuterium
- c) Tritium
- d) None of these
Answer: a) Protium
Explanation:
Protium is the most abundant isotope of hydrogen in the Sun. It undergoes nuclear fusion in the Sun’s core, producing energy through the proton-proton chain reaction.
95. In fusion reactors, why is a combination of deuterium and tritium preferred over other isotopes?
- a) They are the easiest to obtain.
- b) They have the lowest energy requirements for fusion.
- c) They are the most stable.
- d) They produce no neutrons.
Answer: b) They have the lowest energy requirements for fusion.
Explanation:
The fusion of deuterium and tritium requires the lowest temperature and energy compared to other isotopes of hydrogen, making it ideal for use in experimental fusion reactors.
96. Which isotope of hydrogen is produced naturally by cosmic ray interactions in the Earth’s atmosphere?
- a) Protium
- b) Deuterium
- c) Tritium
- d) None of these
Answer: c) Tritium
Explanation:
Tritium is produced naturally in the Earth’s atmosphere when cosmic rays interact with nitrogen and other elements. However, it occurs in very small amounts.
97. Which of the following isotopes is used in heavy water reactors to maintain a sustained nuclear chain reaction?
- a) Protium
- b) Deuterium
- c) Tritium
- d) Oxygen-18
Answer: b) Deuterium
Explanation:
Deuterium, in the form of heavy water (D₂O), is used as a moderator in heavy water reactors to slow down fast neutrons and maintain a sustained nuclear chain reaction.
98. Which isotope of hydrogen is used in glow sticks?
- a) Protium
- b) Deuterium
- c) Tritium
- d) None of these
Answer: c) Tritium
Explanation:
Tritium is used in glow sticks and other luminescent devices, where its radioactive decay causes phosphors to glow without the need for an external power source.
99. Which of the following isotopes of hydrogen has a proton and two neutrons?
- a) Protium
- b) Deuterium
- c) Tritium
- d) None of these
Answer: c) Tritium
Explanation:
Tritium has one proton and two neutrons, making it the heaviest of the three hydrogen isotopes.
100. Which of the following isotopes of hydrogen is commonly used in thermonuclear weapons?
- a) Protium
- b) Deuterium
- c) Tritium
- d) Both b and c
Answer: d) Both b and c
Explanation:
Both deuterium and tritium are used in thermonuclear weapons (hydrogen bombs) as they undergo fusion reactions that release tremendous amounts of energy.
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