Radioactive decay Definition and 216 Threads

A question was originally put in the homework help forum "1 gramm radiates 3,7*10^10 alpha-particles in a second. Find out the half-life" At a glance it looks simple. You start with X number of AMU, it's radiating at a rate of Y, find out how long it takes to get to 0.5X; right? Then I...

A sample of tritium 3 decayed to 94.5% of its original amount after a year. (a) What is the half-life of tritium-3? (b) How long would it take the sample to decay to 20% of its original amount? The only equations given in my book are dm/dt = km and m(t) =...

During radioactive decay, what determines if the emission of a beta particle will be positronic or electronic?

I need a refresher on calculus need to derive this equation, the question is: A --> B --> C and where decay constants: http://img183.imageshack.us/img183/4403/aki2.jpg Derive an expression for the activity of B as a function of time. So what I'm having trouble with is changing the...

Hi, Is it possible to induce decay in a radioactive element by introducing vast amounts of high-energy electrons in the hope that they would be absorbed via electron capture? I was thinking about how to use up all the reactor waste that the US generates (I live in Washington State, a great...

Natural Uranium found in the Earth's crust contains the isotopes A=235 and A=238 in the atom ratio of 7.3*10^-3 to 1. Assuming that the time of formation of the Earth these two isotopes were formed equally, and that the mean lives are 1.03*10^9 years and 6.49*10^9 years respectively, show that...

I was wondering, and it baffles me, how is the strong force involved in radioactive decay? I know ecxatly how the weak force is involved but that's about it. Thanks

Okay, I've got this problem in my Chemistry class. It's about half-lifes and all that. If this is the wrong place to post this, then somebody can move it I guess. I've got a 10.0 g sample of an unknown. They give me the following info, wanting me to plot it on a graph. That's the easy...

The carbon in living matter contains a fixed proportion of the radioactive isotope carbon-14. The carbon-14 in 1.00g of carbon from living matter has an activity of 0.250Bq. The half-life of carbon-14 is 5730. When a plant dies the proportion of carbon-14 decreases due to radioactive decay. A...

Q: A 50-g chunk of charcoal is found in the buried remains of an ancient city destroyed by invaders. The carbon-14 activity of the sample is 200 decays/min. Roughly when was the city destroyed? A: I used R = Ro*e^(-lambda*t) and t1/2 = ln2/lambda t1/2 = 3.834*10^-12 s-1 and 200...

Simple question, but i don't know where to start. The half life of one radioactive isotope of sodium is 2.6 years. Show that its decay constant is 8.4 x 10^-9 s^-1. Thanks in advance, Ben.

Does time dilation effect radioactive decay rates? A quick search on google seems to say no. This would imply that if the twins paradox was executed, that when the traveling twin returned home, after say 2000 Earth years have passed, we would carbon date him at 2000+ years old. What would...

A 2.71g sample of KCL is found to be radioactive, and it is decaying at a constant rate of 4490 Bq. The decays are traced to the ekement potassium and in particular to the isotope K(proton number 40), which constitutes 1.17% of normal potassium. find the half-life of this nuclide( Take molar...

hi I'm new here hope you can help me with this problem nuclei A decays to B and then to C(stable) A and B have the same decay constant, n Initially the amount of A is N(0)>0 while B and C are zero then the amount of A at any time is : N(t)=N(0)exp(-nt) can somebody derive the equation for...

Question #1: Can I speak of an atom decaying because one or more of its particles exceeded "escape velocity" according to statistically observed decay rates and a unit of the particle's former affiliation fell apart post-escape somewhat, and the atom was changed into an isotope or some other...

If you take two identical radioactive samples, place one on Earth and another on a near-lightspeed spaceship, and compare them some time later, will the one left on Earth have undergone comparatively more radioactive decay than the one on the spaceship? If the experiment is repeated by...