Discover the answers to your questions at Westonci.ca, where experts share their knowledge and insights with you. Join our Q&A platform to connect with experts dedicated to providing precise answers to your questions in different areas. Join our Q&A platform to connect with experts dedicated to providing accurate answers to your questions in various fields.

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.