Question

If you have a 350 gram sample of an isotope with a four-year half-life, how much of the sample would remain after three half-lives? Explain your reasoning.

Answer 1

After one half life initial amounts gets half so :-

1. First half life :- 350÷2 = 175 grams
2. second half life :- 175 ÷2 = 87.5 grams
3. third half life :- 87.5 ÷2 = 43.75 grams

so at last of third half life amount left = 43.75 grams

each time amount get half

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