Answer:
Kr-73 = 23.625 sec
Kr-74 = 10.0625 minutes (603.75 seconds)
Kr-76 = 12.95 hours (777 minutes)
Kr-81 = 1.8375 * 10^6 years
Explanation:
What you do is multiply each of those amounts by 7/8.
27 * 7/8 = 189/8 = 23.625
23/2 * 7/8 = 161/16 = 10.0625
74/5 * 7/8 = 518/40 = 259/20 = 12.95
210000 * 7/8 = 1470000/8 = 183750 = 1.8375 * 10^6
Answer:
i think it will be c. The acid in solution A is less concentrated than in solution B and is also a stronger acid than that in solution B. im not for sure
Explanation:
Answer:
I'm so sorry I would love to help you but I have no idea
I got b 5)A sample of pure sodium-24 has an initial mass of 10.0 grams. How many grams of sodium-24 will remain at the end of 4 half-lives?
A. 0.315
B. 0.630
C. 5.00
D. 6.00
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
