Consider the following statements: In a nuclear reactor, self-sustained chain reaction is possible, because:1. more neutrons are released in each of the fission reactions.2. The neutrons immediately take part in the fission process.3. The fast neutrons are slowed down by graphite.4. Every neutron released in the fission reaction initiates further fission. Which of these statements are correct?
✓ Correct answer: a) 1, 2 and 3
ExplanationNuclear fission is the process in which a heavy atomic nucleus, such as uranium-235 or plutonium-239, splits into two smaller nuclei, releasing a large amount of energy.Statement 1 is correct: Each fission reaction releases multiple neutrons, which are crucial for sustaining the chain reaction.Statement 2 is correct: The neutrons produced in fission reactions are used to initiate further fission events.Statement 3 is correct: Graphite (a moderator) slows down fast neutrons, increasing the likelihood that they will cause further fission reactions, thus making reaction sustainable over longer periods.Statement 4 is incorrect: Not every neutron released will necessarily cause further fission, as some neutrons may escape the reactor or fail to cause fission if not properly moderated.288
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