Chapter 13: Nuclei Assertion Reason
These questions of two statements each, printed as Assertion and Reason. While answering these Questions you are required to choose any one of the following four responses.
(A) If both Assertion & Reason are true & the Reason is a correct explanation of the Assertion.
(B) If both Assertion and Reason are true but Reason is not a correct explanation of the Assertion.
(C) If Assertion is true but the Reason is false.
(D) If Assertion & Reason both are false.
Assertion-Reason Questions
- Assertion (A): The mass of a nucleus is less than the sum of the masses of its constituent protons and neutrons.
Reason (R): The mass defect is converted into binding energy, which holds the nucleus together.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): The binding energy per nucleon is a measure of the stability of a nucleus.
Reason (R): A higher binding energy per nucleon means the nucleons are more tightly bound and the nucleus is more stable.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): Heavy nuclei tend to be unstable and undergo radioactive decay.
Reason (R): In heavy nuclei, the repulsive electrostatic forces between protons are not sufficiently balanced by the attractive nuclear forces.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): Alpha particles have a higher ionizing power than beta particles.
Reason (R): Alpha particles are heavier and carry a double positive charge, leading to greater interaction with matter.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): Gamma radiation is more penetrating than alpha or beta radiation.
Reason (R): Gamma rays are high-energy photons with no mass and no charge.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): The half-life of a radioactive substance is constant.
Reason (R): The half-life is a characteristic property of the radioactive substance and does not depend on external conditions.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): The decay constant is inversely proportional to the half-life of a radioactive substance.
Reason (R): The decay constant is a measure of the probability of decay per unit time.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): Nuclear fission is accompanied by the release of a large amount of energy.
Reason (R): The binding energy per nucleon of the fission fragments is greater than that of the original nucleus.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): Nuclear fusion requires extremely high temperatures.
Reason (R): High temperatures provide the necessary kinetic energy to overcome the electrostatic repulsion between nuclei.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): A Geiger-Muller counter can detect alpha, beta, and gamma radiation.
Reason (R): The Geiger-Muller counter measures the ionization produced by the radiation in a gas-filled tube.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): Neutrons are more penetrating than charged particles.
Reason (R): Neutrons have no charge and therefore do not experience electrostatic repulsion as they pass through matter.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): The activity of a radioactive sample decreases over time.
Reason (R): The number of undecayed nuclei in the sample decreases over time, leading to a decrease in the rate of decay.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): In a nuclear reactor, control rods are used to control the rate of fission.
Reason (R): Control rods absorb neutrons, thereby reducing the number of neutrons available to cause further fission.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): Radioactive isotopes are used in medical imaging.
Reason (R): Radioactive isotopes emit radiation that can be detected and used to create images of the body’s internal structures.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): The energy released in a nuclear reaction is much greater than in a chemical reaction.
Reason (R): Nuclear reactions involve changes in the binding energy of the nucleus, which is much larger than the energy changes in chemical reactions.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): The mass number of a nucleus is the sum of the number of protons and neutrons.
Reason (R): Protons and neutrons are the nucleons that make up the nucleus.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): Isotopes of an element have the same chemical properties.
Reason (R): Isotopes have the same number of protons and electrons, which determine chemical properties.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): Radioactive decay is a random process.
Reason (R): The decay of each nucleus occurs independently of others and cannot be predicted exactly when it will occur.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): Beta decay increases the atomic number of a nucleus by one.
Reason (R): In beta decay, a neutron is converted into a proton and an electron, and the electron is emitted as a beta particle.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): The half-life of a radioactive substance can be determined experimentally.
Reason (R): The half-life is the time taken for half of the radioactive nuclei in a sample to decay.
Answer: Both A and R are true and R is the correct explanation of A.