A radioactive substance has a half-life of 10 years.
a. Find the equation that describes the quantity of the substance present at time t using the continuous exponential model.
b. Determine the continuous rate of decay.

For part a, I got the equation: [tex]Q= Q_{0} e^{-0.0693t} [/tex] . Is part b -6.93%? How exactly do you find continuous rate of decay?