A radioactive substance has a half-life of four months. Three-fourth of the substance would decay in:
✓ Correct answer: c) 8 months
ExplanationThe half-life of a radioactive substance is the time it takes for half of the substance to decay.After each half-life:At the end of 1 half-life (4 months), 50% of the substance remains.At the end of 2 half-lives (8 months), 25% of the substance remains, meaning 75% (three-fourths) of the substance has decayed.Thus, it takes 8 months for three-fourths of the substance to decay.305
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