Difficulty: Easy
Correct Answer: conversion of mass into energy
Explanation:
Introduction / Context:Nuclear explosions (fission or fusion) release energy far beyond chemical reactions. Understanding why requires Einstein’s relation E = m * c^2, which links mass loss to enormous energy output. This principle underlies both nuclear power and nuclear weapons.
Given Data / Assumptions:
Concept / Approach:During fission, a heavy nucleus splits into smaller fragments; during fusion, light nuclei combine. In both, the total mass of products is slightly less than that of reactants. The “missing” mass converts to energy as dictated by E = m * c^2. This is neither a chemical process nor a transformation of mechanical energy; it is a nuclear-level mass-to-energy conversion.
Step-by-Step Solution:
Recognize that nuclear binding energy differences create a mass defect.Apply E = m * c^2: small m multiplied by c^2 (a huge number) yields enormous E.Conclude the dominant source is mass-to-energy conversion.Reject options describing chemical or mechanical changes.Verification / Alternative check:Energy per nucleon change in fission/fusion is orders of magnitude higher than in chemical bonds, consistent only with nuclear binding energy differences tied to mass defect.
Why Other Options Are Wrong:
Common Pitfalls:Confusing the mechanism (mass defect) with byproducts like heat and radiation. Heat is a result, not the fundamental source.
Final Answer:conversion of mass into energy
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