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Ann [662]
3 years ago
5

Sodium-24 has a half-life of 15 hours. how many grams of a 900 g sample will remain after 90 hours

Mathematics
1 answer:
raketka [301]3 years ago
4 0

Answer: Option 'B' is correct.

Step-by-step explanation:

Let the initial concentration be

N_0=900\ g

Let concentration after t= 90 hours be N

Since we have given that Sodium-24 has a half life of 15 hours i.e.

t_{\frac{1}{2}}=15

So, According to question,

\text{ Number of half lives }=\frac{t}{t_{\frac{1}{2}}}\\\\\text{ Number of half lives }=\frac{90}{15}\\\\\text{ Number of half lives }=6

As we know that

\frac{N}{N_0}=(\frac{1}{2})^n\\\\N=N_0\times (\frac{1}{2})^n\\\\N=900\times (\frac{1}{2})^6\\\\N=\frac{900}{64}\\\\N=14.0625\ g

Hence, Option 'B' is correct.

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