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Situation: Find the substance’s half-life, in days. • Round your answer to the nearest tenth. A 25 gram sample of a substa
Question
Situation:
Find the substance’s half-life, in days.
• Round your answer to the nearest tenth.
A 25 gram sample of a substance that’s
used for drug research has a k-value of
0.1229.
Enter the correct answer.
N = Noe
-kt
DONE
No = initial mass (at time t = 0)
?
N = mass at time t
k = a positive constant that depends on
the substance itself and on the units
used to measure time
t = time, in days
in progress
0
Mathematics
3 years
2021-07-23T18:50:07+00:00
2021-07-23T18:50:07+00:00 1 Answers
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0
Answers ( )
Answer:
5.6 days
Step-by-step explanation:
We are given;
Initial Mass; N_o = 25 g
Mass at time(t); N_t = 25/2 = 12.5 (I divide by 2 because we are dealing with half life)
k = 0.1229
Formula is given as;
N_t = N_o•e^(-kt)
Plugging in the relevant values;
12.5 = 25 × e^(-0.1229t)
e^(-0.1229t) = 12.5/25
e^(-0.1229t) = 0.5
(-0.1229t) = In 0.5
-0.1229t = -0.6931
t = -0.6931/-0.1229
t = 5.6 days