Understanding Carbon Decay: Solving for Decay Rate

AI Thread Summary
To find the decay rate of carbon, the decay constant and half-life are essential. The decay constant calculated was -1.209x10^-4, and the half-life is 5730 years. The correct formula for activity is Activity = kN, where k is derived from the half-life. The calculated activity of 7.89x10^6 particles per year converts to approximately 15 particles per minute. The initial confusion arose from the unit of measurement, which was clarified to be in minutes.
jimmy42
Messages
50
Reaction score
0
How can I find the decay rate of carbon? I have found the decay constant and I know the half life and the number of atoms. I think I have the data and I have the answer but I think I am using the wrong equation as my answer does not fit the books.

The decay constant I got as -1.209x10^-4

N = 6.5234X10^10

half life = 5730 years.

I tried this:

R = ln(2) N/half life

That did not work.
 
Physics news on Phys.org
The formula for finding the decay constant is: k = (ln2)/(half life) = 0.000121 years^-1

Activity = kN
Activity = (0.000121 years^-1)(6.5234*10^10) = 7.89*10^6 particles per year

It might be possible that they expressed their answer in Becquerel, as it is the SI unit for activity. What answer did they give?
 
Last edited:
The answer was given in minutes, It should be 15
 
jimmy42 said:
The answer was given in minutes, It should be 15
Then the answer is correct.

7.89*10^6 particles per year

(7.89*10^6)/(365*24*60) particles per minutes = 15.0138 particles per minutes

= 15
 
Yes thanks, i didn't think to convert it.
 

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
View full post »

Similar threads

Calculation on spontaneous fission and effect from alpha decay
Replies
23
Views
2K
Carbon-14 Half-Life: Calculating Decays After 50,000 Years
Replies
2
Views
1K
Rate of emission of alpha particle in uranium decay
Replies
2
Views
2K
Radioactive Decay Rates and the Relationship between Decay Constants
Replies
4
Views
2K
Ratio of the rate of decay of R to that of S after 2 hours
Replies
3
Views
1K
Time taken for amount of a nuclear material to remain
Replies
5
Views
2K
Activity of 1 g of carbon if 1 in 10^12 atoms are carbon-14
Replies
11
Views
5K
Determine the value of a decay constant
Replies
13
Views
3K
Calculating Initial Decay Rate of Ga-67 Isotope
Replies
5
Views
3K
What is the orbital radius of a muon captured in the n=1 ground state of Carbon?
Replies
13
Views
3K

Hot Threads

Recent Insights

Back
Top