a radioactive with a half-life of 5 days, has an initial activity of 4000 counts/min(adsbygoogle = window.adsbygoogle || []).push({});

determine the activity after 10 days

well because 1 half life is 5 days, so 10 days must be 2

so 4000/(2^2)

=1000 counts/min is that right?

2. If the initial quantitiy of radioactive material is 200gms determine the amount left after 15 days have elapsed

no of half lives = 3

200/(2^3)

=25 gms is that right?

3. convert 4000 counts per min into bq's

how do i do that?

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# Half-life very difficult!

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