Answer:
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Step-by-step explanation:
Answer:
The substance half-life is of 4.98 days.
Step-by-step explanation:
Equation for an amount of a decaying substance:
The equation for the amount of a substance that decay exponentially has the following format:

In which k is the decay rate, as a decimal.
k-value of 0.1392.
This means that:

Find the substance's half life, in days.
This is t for which
. So







The substance half-life is of 4.98 days.
Percentage increase/decrease is given by (the difference ÷ original value) × 100
The decrease in value is 16500 - 14000 = 2500
The percentage decrease = (2500÷16500) × 100 = 15.2%
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