Question

3. How much of a 75 mg sample of will remain after 75 days if the sample has a half-life of 7.5days?

Answer 1

Answer:

0.073 mg sample will remain

Explanations:

The final amount of a substance after t years given the initial amount and the half life is expressed as:

`A(t)=A_0((1)/(2))^{(t)/(x)}`

where A(t) is the amount after time t

x is the half life

A₀ = initial amount = 75 mg

t = 75 days = 75/365 = 0.2055 years

Half life, x = 7.5 days = 0.02055 years

Substitute these values into the formula given

`\begin{gathered} A=75(0.5)^{(0.2055)/(0.02055)} \\ A\text{ = 75(0.5)}^(10) \\ A\text{ = }0.073\text{ mg} \end{gathered}`

0.073 mg sample will remain