posted by Shay .
Po-210 Ia an alpha emitter with a half-life of 138 days. how many grams of Po-210 remain after 552 days if the sample initially contained 5.80g of Po-210?
Suppose that you start with 1000000 atoms of a particular radioactive isotope. how many half-lives woruld be required to reduce the number of undecayed atoms to fewer than 1000?
k = 0.693/t1/2
Substitute k in the below equation.
ln(No/N) = kt
No = 5.80g
N = ?
K = from above
t = 552 days
Solve for N
For #2, you want 1,000,000/2^n = 1,000
Solve for n. The easy way to do that is to solve for 2^n and then n.