Question

the radioactive substance krypton-91 has a very short half life of about 10 seconds what is the decay constant for this substance

Answer 1

k = -ln2/(half-life). Quick formula for those exponential growth and decay problems.

Answer 2

\[N(t) = No \frac{ 1 }{ 2 }^{-\lambda t}\]

Is this the formula you use ?

Answer 3

\[N(t) = N_0 e^{- \lambda t}\]

Answer 4

\[\lambda=\frac{\ln(2)}{t_{1/2}}\]

Answer 5

ok thanks UnkleRhaukus. Ill use that one since im not really sure what formula to use since the problem doesnt tell me what formula to use.