Question

The half-life of radium is 1620 years. Find the constant k in the formula when the time is given in years. I am supposed to use y=Ce^kt I think.

Answer 1

`e^(1620k)=0.5`
Taking natural logs of both sides, we get:

`1620k=ln\ 0.5=-0.693`

`k=(-0.693)/(1620)=-0.000428`