The question is incomplete, here is the complete question:
Recall that m(t) = m.(1/2)^t/h for radioactive decay, where h is the half-life. Suppose that a 500 g sample of phosphorus-32 decays to 356 g over 7 days. Calculate the half life of the sample.
Answer: The half life of the sample of phosphorus-32 is [tex]14.28days^{-1}[/tex]
Step-by-step explanation:
The equation used to calculate the half life of the sample is given as:
[tex]m(t)=m_o(1/2)^{t/h}[/tex]
where,
m(t) = amount of sample after time 't' = 356 g
[tex]m_o[/tex] = initial amount of the sample = 500 g
t = time period = 7 days
h = half life of the sample = ?
Putting values in above equation, we get:
[tex]356=500\times (\frac{1}{2})^{7/h}\\\\h=14.28days^{-1}[/tex]
Hence, the half life of the sample of phosphorus-32 is [tex]14.28days^{-1}[/tex]