alleryFor radioactive decay (1st order), if 1/8 of initial nuclei remain, how many half-lives elapsed?
A2
B3 (since (1/2)³ = 1/8)
C4
D8
Answer & Solution
Correct answer: B. 3 (since (1/2)³ = 1/8)
N/N₀ = (1/2)^n where n is the number of half-lives. (1/2)^n = 1/8 → n = 3.
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