Question

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?

Answer 1

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?

Answer 2

#1.
k = 0.693/t_1/2
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.

Answer 3

0.3625