Posted by Anonymous on .
Thallium 208 has a halflife of 3.053 min. How long will it take for 120g t decat ot 7.50g

chemistry 
DrBob222,
k = 0.693/t_{1/2}
Substitute k into the equation below:
ln(No/N) = kt.
No = initial = 120g
N = final = 7.50g
k from above.
Solve for t.