3 because of the thing it’s trying to say
Answer: the pH is 11.78
Explanation:Please see attachment for explanation
I believe it is three (3), temperature is the measure of the average Kinetic Energy, while heat is the measure of the transfer of thermal energy.
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: 39.948 grams
Explanation:
The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles Argon, or 39.948 grams