Question

A 25 gram sample of a substance that's used for drug research has a k-value of 0.1229 Find the substance's half-life in days.

Answer 1

No direct answers

Answer 2

Use the general formula for half-life

\(A_t = A_oe^{-kt}\)
\(A_t\) = the mass at half-life point, or \(\frac{A_o}{2}=\frac{25}{2}=12.5\)
k=0.1229
\(A_o=25\)
t, you must find

\(12.5 = 25e^{-0.1229t}\)
Use the inverse of e, ln (natural log) to find t.
\(ln12.5 = ln(25e^{-0.1229t})\)
\(ln12.5 = ln25-0.1229t\)
Use your calculator to evaluate the value of t. That should give you your half life

Answer 3

sorry