A radioactive substance has a decay constant equal to

$4\mathrm{.}8{10}^{-8}{s}^{-1}$

For the steps and strategies involved in solving a similar problem, you may view the following Quick Example $32-11$ video:

REASONING AND SOLUTION

The menter of amens follom in eponential dependence: $N=N$

$q,20$

$T_{\frac{1}{2}}=$

$$

What is the half$-$life of this substance?

Express your answer in years.

$$ y