Asked by Krys

I am confused about how to claculate half lives. Can you explain. ( How much of a 400 gm sample od gold is left after 10.8 days if the half life is 2.7)
Answered by DrBob222
This way.

k = 0.693/t<sub>1/2</sub>
You don't have any units for the half life of 2.7 WHAT? Make sure unit for this agrees with unit below (in days).
Substitute k into the equation below.

ln(No/N) = kt

No = what you start with--400 g
solve for N, the number left after time t.
k from above.
t = time = 10.8 days.
Answered by Krys
2.7 days.. so the answer is 25 g ?
Answered by kiri
1. billion
Answered by Amber
I don't know the answer to your question, but can some one help me with mine?

Question: After six half-lives, what percentage of a radioactive sample will remain?

Please help me!, Thank you.
Answered by anon
Responding to Amber,
Six half lives:
1/2 * 1/2 * 1/2 * 1/2 * 1/2 * 1/2 = 1/64 = 0.015625 = 1.5625%
There are no AI answers yet. The ability to request AI answers is coming soon!