Answer:
[A] = 0.39mg
Explanation:
The radioactive decay of an atom follows the equation:
Ln[A] = -kt + ln[A]₀
Where [A] is actual amount of isotope after time t; k is decay constant and [A]₀ initial amount of isotope
Also, we can write k in therms of half-life:
k = ln2 / Half-life
Solving for k:
k = ln2 / 14.3days
k = 0.04847days⁻¹
Solving in the equation for [A]:
Ln[A] = -0.04847days⁻¹*57.2days + ln[6.3mg]
ln[A] = -0.93193
[A] = 0.39mg
