8. A substance has a half life of 2.347 minutes.
a. If the initial amount of the substance was 110.4 grams, how many half-lives will have passed
before the substance decays to 6.9 grams.
b. What is the total time of the decay?

Answers

Answer 1

Answer:

a.) 4 half lives have passed

b) 9.388 minutes

Step-by-step explanation:

Formula for exponential growth / decay is given as:

[tex]A=A_0b^{\frac{t}{c}}[/tex]

Where [tex]A[/tex] is the final population

[tex]A_0[/tex] is the initial population

[tex]b[/tex] is the growth factor

[tex]c[/tex] is the time taken for the growth 'b'

[tex]t[/tex] is the amount of time

Here, we are given that:

[tex]A[/tex] = 6. 9 grams

[tex]A_0[/tex] = 110.4 grams

[tex]b = \dfrac{1}{2}[/tex]

[tex]c = 2.347[/tex] min

To find:

a.) Number of half lives taken for the decay.

b.) Total time in the decay.

Solution:

a.) Number of half lives taken for the decay is nothing but equal to [tex]\frac{t}{c}[/tex].

Putting the values in the formula, we get:

[tex]6.9=110.4\times \frac{1}2^{\frac{t}{c}}\\\Rightarrow 6.9=110.4\times 0.5^{\frac{t}{c}}\\\Rightarrow 0.0625=0.5^{\frac{t}{c}}\\\Rightarrow \dfrac{t}{c} =4[/tex]

Therefore, the answer is:

4 half lives have passed.

b.) Total time of decay. We have to find the value of [tex]t[/tex] here.

From answer of part a.):

[tex]\dfrac{t}{c} =4\\\Rightarrow \dfrac{t}{2.347} =4\\\Rightarrow t =\bold{9.388\ min}[/tex]


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Step-by-step explanation:

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Answers

Answer:

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Answers

Answer:

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Step-by-step explanation:

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Answers

Answer:

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Step-by-step explanation:

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===================================================================

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===================================================================

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Answers

Answer:

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Answers

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Step-by-step explanation:

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Answers

Answer:

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Step-by-step explanation:

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Answers

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Answers

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Step-by-step explanation:

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