🌟 Structure of the ⚛️Atom🌟
1. Which sub-atomic particle was discovered first?
2. Who proposed the Plum Pudding model of the atom?
Assertion and Reason Questions
3. Assertion (A): Atoms are indivisible and cannot be broken down further.
Reason (R): The discovery of sub-atomic particles proved that atoms are not indivisible.
Reason (R): The discovery of sub-atomic particles proved that atoms are not indivisible.
Multiple Choice Questions (MCQs)
4. Which scientist discovered the neutron?
Assertion and Reason Questions
5. Assertion (A): Electrons revolve around the nucleus in fixed orbits.
Reason (R): Rutherford proposed the concept of quantized energy levels.
Reason (R): Rutherford proposed the concept of quantized energy levels.
6. Match the subatomic particles with their properties:
(1) Electron
(2) Proton
(3) Neutron
(4) Nucleus
(A) Negatively charged
(B) Positively charged
(C) Neutral charge
(D) Contains protons and neutrons
7. What did Dalton’s atomic theory suggest about atoms?
8. According to Thomson’s model, how are electrons arranged in an atom?
9. Which major limitation of Thomson’s model led to its rejection?
10. What was the main conclusion of Rutherford’s gold foil experiment?
11. Why did Rutherford choose gold foil for his experiment?
12. What was the major drawback of Rutherford’s atomic model?
Assertion and Reason Questions
13. Assertion (A): Most of the space inside an atom is empty.
Reason (R): In Rutherford’s experiment, most alpha particles passed through the gold foil without deflection.
Reason (R): In Rutherford’s experiment, most alpha particles passed through the gold foil without deflection.
14. Assertion (A): The nucleus of an atom contains protons and neutrons.
Reason (R): Electrons revolve around the nucleus in fixed orbits.
Reason (R): Electrons revolve around the nucleus in fixed orbits.
15. What was Bohr’s main contribution to atomic theory?
16. How are the energy levels of electrons in an atom represented?
Assertion and Reason Questions
17. Assertion (A): Electrons do not radiate energy while revolving in discrete orbits.
Reason (R): Bohr’s model states that electrons exist in specific energy levels and do not emit energy spontaneously.
Reason (R): Bohr’s model states that electrons exist in specific energy levels and do not emit energy spontaneously.
18. Assertion (A): Bohr’s model was completely accurate in explaining atomic structure.
Reason (R): The model did not account for electron behavior in multi-electron atoms.
Reason (R): The model did not account for electron behavior in multi-electron atoms.
19. What are the discrete orbits in Bohr’s model called?
20. What happens when an electron jumps from a higher energy level to a lower one?
21. What did Bohr propose about electron orbits?
22. What was the key finding of Rutherford’s gold foil experiment?
23. Why was Rutherford’s model considered incomplete?
24. Who discovered neutrons?
25. What is the charge of a neutron?
26. Why do neutrons contribute to atomic mass?
27. Assertion: Neutrons are present in the nucleus of all atoms except hydrogen.
Reason: Hydrogen has only one proton and no neutrons.
Reason: Hydrogen has only one proton and no neutrons.
28. Match the following:
29. What is the maximum number of electrons in the M-shell?
30. Which of the following rules is followed when electrons are distributed in shells?
31. What is the maximum number of electrons that can be accommodated in the outermost shell?
32. Which of the following statements is correct about the electron distribution in atoms?
33. Assertion: The number of electrons in a shell follows the formula 2n², where n is the shell number.
Reason: This formula determines the maximum number of electrons in a given shell.
Reason: This formula determines the maximum number of electrons in a given shell.
34. How many electrons can the L-shell hold?
35. What is the valency of magnesium (Mg)?
36. What is the valency of aluminium (Al)?
37. What is the valency of fluorine (F)?
38. What is the valency of oxygen (O)?
39. What is the valency of chlorine (Cl)?
40. Which element has a valency of 0?
Atomic Structure and Valency Quiz
41. Match the following:
42. Match the following elements with their valencies:
43. What is the atomic number of hydrogen?
44. The mass number of an atom is the sum of:
45. What is the atomic number of carbon?
46. What is the mass number of nitrogen?
47. The atomic number is defined as:
48. Assertion: The atomic number determines the identity of an element.
Reason: The atomic number is the number of protons in the nucleus of an atom.
Reason: The atomic number is the number of protons in the nucleus of an atom.
49. Assertion: Mass number of an atom is always greater than or equal to its atomic number.
Reason: The mass number is the sum of protons and neutrons, which are always more than or equal to the number of protons.
Reason: The mass number is the sum of protons and neutrons, which are always more than or equal to the number of protons.
50. Assertion: Electrons contribute significantly to the mass of an atom.
Reason: The mass of an atom is primarily due to protons and neutrons, not electrons.
Reason: The mass of an atom is primarily due to protons and neutrons, not electrons.
51. Assertion: The atomic number of carbon is 6.
Reason: Carbon has 6 protons in its nucleus, which makes its atomic number 6.
Reason: Carbon has 6 protons in its nucleus, which makes its atomic number 6.
52. Assertion: The number of protons and neutrons are equal in a neutral atom.
Reason: In a neutral atom, the number of protons is balanced by the number of electrons, while neutrons do not affect neutrality.
Reason: In a neutral atom, the number of protons is balanced by the number of electrons, while neutrons do not affect neutrality.
53. Assertion: Isotopes are atoms of the same element with the same atomic number but different mass numbers.
Reason: Isotopes of an element have similar chemical properties but different physical properties.
Reason: Isotopes of an element have similar chemical properties but different physical properties.
54. Assertion: Chlorine exists in nature as a mixture of two isotopes, chlorine-35 and chlorine-37.
Reason: The mass number of chlorine is the weighted average of its isotopes, which is 35.5 u.
Reason: The mass number of chlorine is the weighted average of its isotopes, which is 35.5 u.
55. Assertion: Isobars are atoms of different elements with the same mass number.
Reason: Isobars always have the same atomic number.
Reason: Isobars always have the same atomic number.
56. Assertion: The atomic number of an isotope is the same as that of the element.
Reason: Isotopes of an element have the same number of protons and hence the same atomic number.
Reason: Isotopes of an element have the same number of protons and hence the same atomic number.
57. Assertion: The average atomic mass of chlorine is 35.5 u.
Reason: Chlorine has two isotopes, chlorine-35 and chlorine-37, with different abundances, which results in an average atomic mass of 35.5 u.
Reason: Chlorine has two isotopes, chlorine-35 and chlorine-37, with different abundances, which results in an average atomic mass of 35.5 u.
58. Which of the following elements has isotopes with mass numbers 14 and 12?
a) Carbon
b) Hydrogen
c) Oxygen
d) Nitrogen
a) Carbon
b) Hydrogen
c) Oxygen
d) Nitrogen
59. Which of the following elements has isobars with mass number 40?
a) Calcium and Argon
b) Magnesium and Nitrogen
c) Oxygen and Nitrogen
d) Chlorine and Neon
a) Calcium and Argon
b) Magnesium and Nitrogen
c) Oxygen and Nitrogen
d) Chlorine and Neon
60. Which of the following is true about isotopes?
a) They have the same number of protons but different numbers of neutrons.
b) They have the same mass number but different atomic numbers.
c) They have the same atomic number and different atomic masses.
d) They have different chemical properties and the same physical properties.
a) They have the same number of protons but different numbers of neutrons.
b) They have the same mass number but different atomic numbers.
c) They have the same atomic number and different atomic masses.
d) They have different chemical properties and the same physical properties.
61. Which isotope of hydrogen is commonly used in nuclear fusion reactions?
a) Protium
b) Deuterium
c) Uranium
d) None of the above
a) Protium
b) Deuterium
c) Uranium
d) None of the above
62. What is the mass number of an isotope of an element that has 8 protons and 9 neutrons?
a) 8
b) 9
c) 16
d) 17
a) 8
b) 9
c) 16
d) 17
63. Which of the following isotopes of iodine is used in medical treatments for thyroid problems?
a) Iodine-127
b) Iodine-131
c) Iodine-132
d) Iodine-135
a) Iodine-127
b) Iodine-131
c) Iodine-132
d) Iodine-135
64. What is the atomic number of an element if it has 13 protons in its nucleus?
a) 13
b) 12
c) 14
d) 11
a) 13
b) 12
c) 14
d) 11
65. Which of the following is true for an isotope of chlorine with a mass number of 37?
a) It has the same chemical properties as chlorine-35.
b) It has 35 protons.
c) It has 37 neutrons.
d) It has 18 electrons.
a) It has the same chemical properties as chlorine-35.
b) It has 35 protons.
c) It has 37 neutrons.
d) It has 18 electrons.
66. What does the mass number of an atom represent?
a) The number of protons in the nucleus
b) The sum of the protons and neutrons in the nucleus
c) The number of neutrons in the nucleus
d) The total number of electrons in the atom
a) The number of protons in the nucleus
b) The sum of the protons and neutrons in the nucleus
c) The number of neutrons in the nucleus
d) The total number of electrons in the atom
67. Which element has an atomic number of 8 and mass number of 16?
a) Oxygen
b) Nitrogen
c) Carbon
d) Fluorine
a) Oxygen
b) Nitrogen
c) Carbon
d) Fluorine
68. Which of the following is NOT a characteristic of isotopes?
a) Isotopes have the same chemical properties.
b) Isotopes have the same number of protons.
c) Isotopes have different mass numbers.
d) Isotopes have different numbers of electrons.
a) Isotopes have the same chemical properties.
b) Isotopes have the same number of protons.
c) Isotopes have different mass numbers.
d) Isotopes have different numbers of electrons.
69. The isotope of which element is used in nuclear reactors as a fuel?
a) Carbon
b) Uranium
c) Chlorine
d) Iodine
a) Carbon
b) Uranium
c) Chlorine
d) Iodine
70. What is the mass number of an isotope with 10 protons and 12 neutrons?
a) 10
b) 12
c) 22
d) 20
a) 10
b) 12
c) 22
d) 20
71. Which of the following is the most likely explanation for the atomic mass of chlorine being 35.5 u?
a) The mass of a chlorine atom is the average of the masses of chlorine-35 and chlorine-37 isotopes.
b) Chlorine-35 is more abundant than chlorine-37, so the average mass is closer to 37.
c) Chlorine-37 is more abundant than chlorine-35, so the average mass is closer to 35.
d) Chlorine atoms contain neutrons of different masses.
a) The mass of a chlorine atom is the average of the masses of chlorine-35 and chlorine-37 isotopes.
b) Chlorine-35 is more abundant than chlorine-37, so the average mass is closer to 37.
c) Chlorine-37 is more abundant than chlorine-35, so the average mass is closer to 35.
d) Chlorine atoms contain neutrons of different masses.
72. Which of the following statements is true about the isotopes of an element?
a) Isotopes of an element have different atomic numbers.
b) Isotopes of an element have different chemical properties.
c) Isotopes of an element have the same number of protons and electrons.
d) Isotopes of an element have different numbers of electrons.
a) Isotopes of an element have different atomic numbers.
b) Isotopes of an element have different chemical properties.
c) Isotopes of an element have the same number of protons and electrons.
d) Isotopes of an element have different numbers of electrons.
73. The atomic number of an element is 6. How many electrons are there in the K, L, and M shells for a neutral atom of this element?
a) K = 2, L = 4, M = 0
b) K = 2, L = 4, M = 2
c) K = 2, L = 2, M = 2
d) K = 3, L = 3, M = 0
a) K = 2, L = 4, M = 0
b) K = 2, L = 4, M = 2
c) K = 2, L = 2, M = 2
d) K = 3, L = 3, M = 0
74. What is the relationship between atomic number (Z) and mass number (A)?
a) Mass number is always less than atomic number.
b) Atomic number is always less than mass number.
c) Atomic number equals mass number.
d) Atomic number and mass number are not related.
a) Mass number is always less than atomic number.
b) Atomic number is always less than mass number.
c) Atomic number equals mass number.
d) Atomic number and mass number are not related.
75. What is the main difference between isotopes and isobars?
a) Isotopes have the same mass number but different atomic numbers.
b) Isobars have the same mass number but different atomic numbers.
c) Isotopes have different chemical properties.
d) Isobars have the same chemical properties.
a) Isotopes have the same mass number but different atomic numbers.
b) Isobars have the same mass number but different atomic numbers.
c) Isotopes have different chemical properties.
d) Isobars have the same chemical properties.
76. An atom has 2 electrons in its K shell, 8 electrons in its L shell, and 8 electrons in its M shell. What is its atomic number?
a) 18
b) 10
c) 12
d) 8
a) 18
b) 10
c) 12
d) 8
77. According to Rutherford’s experiment, which of the following conclusions is correct about the atomic model?
a) The atom has a dense central nucleus with positive charge.
b) The atom is composed of electrons, protons, and neutrons in a uniform distribution.
c) The electrons revolve in circular orbits without losing energy.
d) The atom is uniformly filled with positive charge and electrons are scattered.
a) The atom has a dense central nucleus with positive charge.
b) The atom is composed of electrons, protons, and neutrons in a uniform distribution.
c) The electrons revolve in circular orbits without losing energy.
d) The atom is uniformly filled with positive charge and electrons are scattered.
78. In Bohr's model of the atom, which of the following statements is true regarding electron energy levels?
a) Electrons can exist in any orbit around the nucleus.
b) Electrons can only occupy specific orbits with fixed energies.
c) The energy of electrons increases as they move closer to the nucleus.
d) Electrons lose energy continuously as they revolve around the nucleus.
a) Electrons can exist in any orbit around the nucleus.
b) Electrons can only occupy specific orbits with fixed energies.
c) The energy of electrons increases as they move closer to the nucleus.
d) Electrons lose energy continuously as they revolve around the nucleus.
79. What was the key observation of the gold foil experiment conducted by Rutherford that led to the discovery of the atomic nucleus?
a) Most of the alpha particles passed through the foil without deflection.
b) Alpha particles were deflected at large angles.
c) Some alpha particles bounced back from the foil.
d) A small fraction of alpha particles were absorbed by the foil.
a) Most of the alpha particles passed through the foil without deflection.
b) Alpha particles were deflected at large angles.
c) Some alpha particles bounced back from the foil.
d) A small fraction of alpha particles were absorbed by the foil.
80. According to the quantum mechanical model of the atom, which of the following statements is true about the position of an electron?
a) Electrons move in fixed orbits.
b) The exact position and momentum of an electron cannot be determined simultaneously.
c) Electrons are found in a defined path with a specific momentum.
d) Electrons are always stationary around the nucleus.
a) Electrons move in fixed orbits.
b) The exact position and momentum of an electron cannot be determined simultaneously.
c) Electrons are found in a defined path with a specific momentum.
d) Electrons are always stationary around the nucleus.
81. Which of the following is true about the Bohr model of the atom?
a) The energy of an electron increases when it moves to a lower orbit.
b) Electrons can emit energy only when they move to higher orbits.
c) Electrons are restricted to specific orbits or energy levels.
d) The Bohr model is invalid for elements beyond hydrogen.
a) The energy of an electron increases when it moves to a lower orbit.
b) Electrons can emit energy only when they move to higher orbits.
c) Electrons are restricted to specific orbits or energy levels.
d) The Bohr model is invalid for elements beyond hydrogen.
82. Which of the following experimental evidence contradicted Rutherford’s model of the atom?
a) The observation that atoms emit discrete spectral lines.
b) The discovery of the neutron.
c) The result of the gold foil experiment.
d) The observation that electrons are moving in fixed orbits.
a) The observation that atoms emit discrete spectral lines.
b) The discovery of the neutron.
c) The result of the gold foil experiment.
d) The observation that electrons are moving in fixed orbits.
83. Which of the following statements correctly applies to both Bohr’s and quantum mechanical models of the atom?
a) Electrons exist in discrete energy levels.
b) Electrons are found in fixed orbits with definite radii.
c) Electrons can only absorb or emit energy in fixed amounts.
d) Electrons can be described by wave functions or probability distributions.
a) Electrons exist in discrete energy levels.
b) Electrons are found in fixed orbits with definite radii.
c) Electrons can only absorb or emit energy in fixed amounts.
d) Electrons can be described by wave functions or probability distributions.
84. What contradiction did Rutherford’s atomic model fail to explain, which was later addressed by Bohr’s model?
a) The stability of the atom.
b) The discrete nature of atomic spectra.
c) The existence of neutrons.
d) The charge distribution within the atom.
a) The stability of the atom.
b) The discrete nature of atomic spectra.
c) The existence of neutrons.
d) The charge distribution within the atom.
85. Which of the following observations led to the development of the concept of quantized energy levels for electrons in Bohr’s model of the atom?
a) The discovery of the electron by J.J. Thomson.
b) The absorption and emission spectra of hydrogen.
c) The existence of protons in the atomic nucleus.
d) The deflection of alpha particles in Rutherford’s experiment.
a) The discovery of the electron by J.J. Thomson.
b) The absorption and emission spectra of hydrogen.
c) The existence of protons in the atomic nucleus.
d) The deflection of alpha particles in Rutherford’s experiment.
86. According to the quantum mechanical model of the atom, which of the following is true about electron orbitals?
a) Orbitals have definite paths and fixed energies.
b) The location of an electron can be determined precisely in an orbital.
c) Orbitals represent regions of space where an electron is most likely to be found.
d) Electrons move in a continuous orbit around the nucleus.
a) Orbitals have definite paths and fixed energies.
b) The location of an electron can be determined precisely in an orbital.
c) Orbitals represent regions of space where an electron is most likely to be found.
d) Electrons move in a continuous orbit around the nucleus.
87. In the Bohr model, which of the following is true about the emission of radiation when an electron transitions from a higher to a lower energy level?
a) The electron absorbs energy, and the energy is emitted as a photon.
b) The electron emits a photon with energy equal to the difference in energy between the two levels.
c) The energy emitted is continuous across the spectrum.
d) The electron remains stationary at the lower energy level after emitting radiation.
a) The electron absorbs energy, and the energy is emitted as a photon.
b) The electron emits a photon with energy equal to the difference in energy between the two levels.
c) The energy emitted is continuous across the spectrum.
d) The electron remains stationary at the lower energy level after emitting radiation.
88. Which of the following is a feature that distinguishes the quantum mechanical model of the atom from the Bohr model?
a) The idea that electrons are confined to specific orbits.
b) The inclusion of a probability distribution for the location of electrons.
c) The concept that electrons emit radiation when they move to lower energy levels.
d) The model only applies to hydrogen atoms.
a) The idea that electrons are confined to specific orbits.
b) The inclusion of a probability distribution for the location of electrons.
c) The concept that electrons emit radiation when they move to lower energy levels.
d) The model only applies to hydrogen atoms.
89. Assertion: The energy levels in the Bohr model of the atom are quantized.
Reason: The energy of an electron in a specific orbit is fixed and does not change unless the electron jumps to a higher or lower orbit.
a) Both Assertion and Reason are correct, and Reason is the correct explanation of Assertion.
b) Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
c) Assertion is correct, but Reason is incorrect.
d) Assertion is incorrect, but Reason is correct.
Reason: The energy of an electron in a specific orbit is fixed and does not change unless the electron jumps to a higher or lower orbit.
a) Both Assertion and Reason are correct, and Reason is the correct explanation of Assertion.
b) Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
c) Assertion is correct, but Reason is incorrect.
d) Assertion is incorrect, but Reason is correct.
90. Assertion: The Heisenberg Uncertainty Principle states that the position and momentum of a particle cannot both be precisely measured at the same time.
Reason: The uncertainty arises due to the interaction between the observer and the observed particle.
a) Both Assertion and Reason are correct, and Reason is the correct explanation of Assertion.
b) Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
c) Assertion is correct, but Reason is incorrect.
d) Assertion is incorrect, but Reason is correct.
Reason: The uncertainty arises due to the interaction between the observer and the observed particle.
a) Both Assertion and Reason are correct, and Reason is the correct explanation of Assertion.
b) Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
c) Assertion is correct, but Reason is incorrect.
d) Assertion is incorrect, but Reason is correct.
91. Assertion: According to Bohr’s model, electrons can move in discrete orbits around the nucleus without emitting radiation.
Reason: Electrons emit radiation only when they transition between energy levels, which results in the emission of photons.
a) Both Assertion and Reason are correct, and Reason is the correct explanation of Assertion.
b) Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
c) Assertion is correct, but Reason is incorrect.
d) Assertion is incorrect, but Reason is correct.
Reason: Electrons emit radiation only when they transition between energy levels, which results in the emission of photons.
a) Both Assertion and Reason are correct, and Reason is the correct explanation of Assertion.
b) Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
c) Assertion is correct, but Reason is incorrect.
d) Assertion is incorrect, but Reason is correct.
92. Assertion: Rutherford’s gold foil experiment led to the discovery of the atomic nucleus.
Reason: The deflection of alpha particles from the gold foil indicated the presence of a dense and positively charged center in the atom.
a) Both Assertion and Reason are correct, and Reason is the correct explanation of Assertion.
b) Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
c) Assertion is correct, but Reason is incorrect.
d) Assertion is incorrect, but Reason is correct.
Reason: The deflection of alpha particles from the gold foil indicated the presence of a dense and positively charged center in the atom.
a) Both Assertion and Reason are correct, and Reason is the correct explanation of Assertion.
b) Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
c) Assertion is correct, but Reason is incorrect.
d) Assertion is incorrect, but Reason is correct.
93. Assertion: The quantum mechanical model of the atom replaces fixed orbits with orbitals.
Reason: Orbitals represent regions of space where there is a high probability of finding an electron, unlike fixed orbits in the Bohr model.
a) Both Assertion and Reason are correct, and Reason is the correct explanation of Assertion.
b) Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
c) Assertion is correct, but Reason is incorrect.
d) Assertion is incorrect, but Reason is correct.
Reason: Orbitals represent regions of space where there is a high probability of finding an electron, unlike fixed orbits in the Bohr model.
a) Both Assertion and Reason are correct, and Reason is the correct explanation of Assertion.
b) Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
c) Assertion is correct, but Reason is incorrect.
d) Assertion is incorrect, but Reason is correct.
94. Assertion: In Bohr's model, the electrons revolve in fixed orbits without radiating energy.
Reason: Electrons in these fixed orbits do not lose energy because their motion is quantized.
a) Both Assertion and Reason are correct, and Reason is the correct explanation of Assertion.
b) Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
c) Assertion is correct, but Reason is incorrect.
d) Assertion is incorrect, but Reason is correct.
Reason: Electrons in these fixed orbits do not lose energy because their motion is quantized.
a) Both Assertion and Reason are correct, and Reason is the correct explanation of Assertion.
b) Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
c) Assertion is correct, but Reason is incorrect.
d) Assertion is incorrect, but Reason is correct.
95. Assertion: The atomic number of an element is equal to the number of protons in its nucleus.
Reason: Atomic number defines the identity of the element and determines its position in the periodic table.
a) Both Assertion and Reason are correct, and Reason is the correct explanation of Assertion.
b) Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
c) Assertion is correct, but Reason is incorrect.
d) Assertion is incorrect, but Reason is correct.
Reason: Atomic number defines the identity of the element and determines its position in the periodic table.
a) Both Assertion and Reason are correct, and Reason is the correct explanation of Assertion.
b) Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
c) Assertion is correct, but Reason is incorrect.
d) Assertion is incorrect, but Reason is correct.
96. Assertion: Isotopes have the same chemical properties because they have the same number of electrons.
Reason: The number of neutrons in an atom does not affect the chemical properties.
a) Both Assertion and Reason are correct, and Reason is the correct explanation of Assertion.
b) Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
c) Assertion is correct, but Reason is incorrect.
d) Assertion is incorrect, but Reason is correct.
Reason: The number of neutrons in an atom does not affect the chemical properties.
a) Both Assertion and Reason are correct, and Reason is the correct explanation of Assertion.
b) Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
c) Assertion is correct, but Reason is incorrect.
d) Assertion is incorrect, but Reason is correct.
97. Assertion: The Bohr model could not explain the spectra of atoms with more than one electron.
Reason: The Bohr model was based on the concept of quantized orbits, which works only for hydrogen-like atoms with a single electron.
a) Both Assertion and Reason are correct, and Reason is the correct explanation of Assertion.
b) Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
c) Assertion is correct, but Reason is incorrect.
d) Assertion is incorrect, but Reason is correct.
Reason: The Bohr model was based on the concept of quantized orbits, which works only for hydrogen-like atoms with a single electron.
a) Both Assertion and Reason are correct, and Reason is the correct explanation of Assertion.
b) Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
c) Assertion is correct, but Reason is incorrect.
d) Assertion is incorrect, but Reason is correct.
98. Assertion: The mass number of an atom is the total number of protons and neutrons in its nucleus.
Reason: The atomic number indicates the number of protons, and mass number is the sum of protons and neutrons.
a) Both Assertion and Reason are correct, and Reason is the correct explanation of Assertion.
b) Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
c) Assertion is correct, but Reason is incorrect.
d) Assertion is incorrect, but Reason is correct.
Reason: The atomic number indicates the number of protons, and mass number is the sum of protons and neutrons.
a) Both Assertion and Reason are correct, and Reason is the correct explanation of Assertion.
b) Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
c) Assertion is correct, but Reason is incorrect.
d) Assertion is incorrect, but Reason is correct.
99. Match the following and select the correct option.
Column I
(A) Atomic Number
(B) Neutron
(C) Isotope
(D) Bohr's Model
Column II
(i) Same chemical properties but different physical properties
(ii) Number of protons in the nucleus of an atom
(iii) Explains electron orbitals for hydrogen-like atoms
(iv) Particle with no charge
Column I
(A) Atomic Number
(B) Neutron
(C) Isotope
(D) Bohr's Model
Column II
(i) Same chemical properties but different physical properties
(ii) Number of protons in the nucleus of an atom
(iii) Explains electron orbitals for hydrogen-like atoms
(iv) Particle with no charge
100. Match the following and select the correct option.
Column I
(A) Proton
(B) Electron
(C) Atomic Mass
(D) Isobars
Column II
(i) Equal to the number of neutrons in an atom of a given isotope
(ii) Particle with a positive charge
(iii) Different elements with the same mass number
(iv) Orbital with a negative charge
Column I
(A) Proton
(B) Electron
(C) Atomic Mass
(D) Isobars
Column II
(i) Equal to the number of neutrons in an atom of a given isotope
(ii) Particle with a positive charge
(iii) Different elements with the same mass number
(iv) Orbital with a negative charge
101. Match the following and select the correct option.
Column I
(A) Atomic Number
(B) Mass Number
(C) Isotopes
(D) Bohr Model
Column II
(i) Same number of protons but different number of neutrons
(ii) Explains the electron orbits in hydrogen atom
(iii) Sum of protons and neutrons in an atom
(iv) Defines the identity of an element
Column I
(A) Atomic Number
(B) Mass Number
(C) Isotopes
(D) Bohr Model
Column II
(i) Same number of protons but different number of neutrons
(ii) Explains the electron orbits in hydrogen atom
(iii) Sum of protons and neutrons in an atom
(iv) Defines the identity of an element
102. Match the following and select the correct option.
Column I
(A) Bohr's Postulate
(B) Isotope of Hydrogen
(C) Atomic Number of Carbon
(D) Mass Number of Hydrogen
Column II
(i) 1
(ii) 12
(iii) Protium
(iv) Electrons revolve in circular orbits
Column I
(A) Bohr's Postulate
(B) Isotope of Hydrogen
(C) Atomic Number of Carbon
(D) Mass Number of Hydrogen
Column II
(i) 1
(ii) 12
(iii) Protium
(iv) Electrons revolve in circular orbits
Please don not use wrong word