The radioactive decay obeys first order kinetics
the rate law expression for radioactive decay is
![ln\frac{[A_{0}]}{[A_{t}]}=kt](https://tex.z-dn.net/?f=ln%5Cfrac%7B%5BA_%7B0%7D%5D%7D%7B%5BA_%7Bt%7D%5D%7D%3Dkt)
Where
A0 = initial concentration
At = concentration after time "t"
t = time
k = rate constant
For first order reaction the relation between rate constant and half life is:
Let us calculate k
k = 0.693 / 72 = 0.009625 years⁻¹
Given
At = 0.25 A0
time = 144 years
So after 144 years the sample contains 25% parent isotope and 75% daughter isotopes**
Simply two half lives
Answer:
a mixture is a material made up of two or more different substances which are physically combined.
Answer: Universal law refers to as legal legitimacy, where those principles and rules are for governing the country. They are most universal in (AATPB) acceptability, applicability, translation, and philosophical basis. They are also considered to be most legitimate.
So basically the answer is A
They are in effect all the time.
Explanation:
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