Number of atoms remaining after 3 half-lives:
AN₀
BN₀/2
CN₀/8 (= N₀ × (1/2)³)
DN₀/4
Answer & Solution
Correct answer: C. N₀/8 (= N₀ × (1/2)³)
After n half-lives: N = N₀ × (1/2)^n. n=3: N₀/8. Independent of initial amount; exponential decay.
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