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How much nitrogen-13 would be left after 40 minutes if the sample started at 4g

1 Answer

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Answer:

0.248 g

Step-by-step explanation:

We are given;

  • Time as 40 minutes
  • Original amount of N-13

We are required to calculate the amount left after decay.

  • We need to know the half life of N-13 first;
  • Half life of N-13 is 9 minutes 58 seconds (9.965 minutes0

We are going to use the formula;

  • Remaining amount = Original amount × 0.5^n

That is; N = N₀ × 0.5^n , where n is the number of half lives.

n = 40 minutes ÷ 9.965 minutes

= 4.014

Therefore;

N = 4 g × 0.5^4.014

= 0.248 g

Therefore, the mass of Nitrogen-13 that will be left is 0.248 g

User DomBat
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