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Question
Which radioactive isotope would have the longer half-life 15O or 19O? (Given rate constants for 15O and 19O are 5.63 × 10–3 s–1 and k = 2.38 × 10–2 s–1 respectively.)
Options
15O
19O
Both will have the same half-life
None of the above, information given is insufficient
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Solution
15O
Explanation:
The rate constant for the decay of 15O is less than that for 19O. Therefore, the rate of decay of 15O will be slower and will have a longer half-life.
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