Answer:
1.238 years will it take
Step-by-step explanation:
The isotope decay of an atom follows the equation:
Ln[A] = -kt + ln[A]₀
Where [A] could be taken as the amount of the isotope after t years
[A] = 1.00mg
t = ?
k is the decay constant; k = ln2 / Half-life
k = ln 2 / 2.86 years = 0.2424 years⁻¹
[A]₀ is the initial amount of the isotope = 1.35mg
Replacing:
ln1 = -0.2424years⁻¹*t + ln 1.35
0.2424years⁻¹*t = ln 1.35
t =
1.238 years will it take