Answer: 7 years
Step-by-step explanation:
[tex]t_{\frac{1}{2} }[/tex] = In2 / ∧
since the half life is given , we have :
22 = In 2/ ∧
∧ = In2/22
∧ = 0.032
Recall the formula for half life:
[tex]\frac{N(t)}{N(0)}[/tex] = [tex]e^{-∧t}[/tex]
Therefore:
0.80 = [tex]e^{-0.032t}[/tex]
Take the In of both sides
In 0.80 = - 0.032t
t = In 0.80 / - 0.032
t = 7 years
