Looking for trustworthy answers? Westonci.ca is the ultimate Q&A platform where experts share their knowledge on various topics. Connect with a community of experts ready to help you find accurate solutions to your questions quickly and efficiently. Experience the convenience of finding accurate answers to your questions from knowledgeable experts on our platform.

The half-life of Radium-226 is 1590 years. If a sample contains 400 mg, how many mg will remain after 1000
years?

Sagot :

Answer:

258.65 mg will be remain after 1000 years

Step-by-step explanation:

This problem can be solved several ways, I prefer the natural log approach for reasons I won’t go into here:

Activity final = Activity initial e^-kt, where

k = the decay constant, = ln2/half life = 0.693/1590, = 0.000436/year

t = the decay time, in the same time base as k

The problem can be worked in units of activity, mass, or number of atoms.

400 x e^-0.000436 x 1000 = 400 x e^-.436 = 258.65 mg

you can check this by estimating. There is about 2/3 of a half life, so there should be more than 200 mg, which would be the value at one half life.