Nuclear decay Definition and 73 Threads

I don't know how to solve the questions that my lecturer gave me. I not understand about probability of half life. Can anyone explain to me and help me solve the questions as well? My lecturer ask us to prove the probability as shown in the picture.

http://arxiv.org/PS_cache/arxiv/pdf/1106/1106.1470v1.pdf "Evidence for Time-Varying Nuclear Decay Rates: Experimental Results and Their Implications for New Physics" Authors: Ephraim Fischbach, Jere H. Jenkins, Peter A. Sturrock (Submitted on 7 Jun 2011) Abstract: Unexplained annual...

Homework Statement How many half-lives must elapse until (a) 90% and (b) 99% of a radioactive sample of atoms has decayed? Homework Equations N=No(1/2)^(t/t1/2) N=No(1/2)^(n) The Attempt at a Solution The part of the solution I don't understand is how to get the second...

Homework Statement If we have the following partial decay chain: N1 -> N2 -> N3 where N1 is the number of nuclei of species 1, etc. and N1 -> N2, not via a decay but by the reaction such as N1 + neutron -> N2 + photon and we know this rate of formation of N2, say 'a'. I then get the...

If we have the following partial decay chain: N1 -> N2 -> N3 where N1 is the number of nuclei of species 1, etc. and N1 -> N2, not via a decay but by the reaction such as N1 + neutron -> N2 + photon and we know this rate of formation of N2, say 'a'. I then get the following rate...

I can offer no further insight.

Nuclear decay and the "age" of atoms. All atomic nuclei heavier than hydrogen were created in stars and would therefore seem to have different ages relative to some specific spacetime reference. Nuclear decay wrt a single atom is taken to be a temporally random event, but is it plausible to...

hello there! your help is really appreciated. 1.For the Ruther alpha-particle scattering experiment, how come we are only concerned with the nucleus of the gold with repulsion on the alpha particle? what about the electrons in gold? Don't they attract the alpha particle? 2. To calculate...

Homework Statement 60Co, half life = 5.2 years, decays by emittion of a beta particle (0.31 MeV) and two gamma particles (1.71MeV and 1.33MeV). what is the minimum initial mass needed of 60Co that will have an activity of at least 10Ci after 30 months? Homework Equations half life =...

This is an interesting observation to explain. Nuclear decay rates change depending on the Earth's distance from the sun. The logical conclusion is some solar parameter directly affects the Earth in a manner that affects nuclear decay rates. It is interesting to note that there is a phase...

Homework Statement A stationary uranium-238 nucleus undergoes alpha-decay. What is the ratio of the daughter nucleus to that of the alpha-particle? P.S. It's a practice problem for which I had the final answer, but I'm not sure how to reach it. Homework Equations I guess it's based on...

Homework Statement Background info: The first order rate of nuclear decay of an isotope depends only upon the isotope, not its chemical form or temperature. The half-life for decay of carbon-14 is 5730 years. Assume that the amount of C-14 present in the atmosphere as CO2 and therefore in a...

1-Half life is the time it takes for half of the nuclei in a sample of radioactive material to decay(Am I right?). Why does the first nucleas that decays,decay first and the one that decays in the end, decay in the end? What's the difference between the two nuclei or what causes this the nuclei...

What does "random" mean wrt nuclear decay? From what I understand, the process of nuclear decay proceeds at a very predictable rate. Given a lump of say, U-235, half of all the nuclei in the lump will have decayed after 700 my. There is no way, though, to determine which nuclei in the lump...

Homework Statement The half-life of an isotope of phosphorus is 14 days. If sample contains 2.9 × 10^16 decays such nuclei, determine its activity. Answer in units of Ci. Homework Equations / The Attempt at a Solution I know that one Ci is equal to 3.7*10^10 bq (or decay per second), I'm...

as above.

http://arxiv.org/abs/0808.3283 This is weird as hell. As far as I knew, nuclear decay rates were not affected by anything, except beta decay under electromagnetic fields. This could possibly have huge consequences in other sciences. Personally, I immediately went to post this in Earth...

1. Is thermal noise truly random? By truly random I mean can you not predict the next value even if you knew everything permitted about the electrons producing the effect. Does this follow from the math of quantum physics? 2. What about nuclear decay is it truly random?

Hi, While googling around further, I came across this reference: http://www.springerlink.com/content/882432575m335467/ That sounds significant. 210Po is supposed to be a significant alpha emitter, and has been used in Radioisotope Thermal Generators. So enhancing its decay rate by 5-8%...

Homework Statement Derive Bateman equation for a decay chain a->b->c->d where each decays with a given mean life let decay constant be L, where L=1/mean life Na(0)=No, Nb(0)=Nc(0)=Nd(0)=0 Homework Equations Want to derive Nb(t)={(No)(La)/(Lb-La)}*{exp[-La*t]-exp[-Lb*t]} extend for...

Radioactive decay is normally characterised by 'the rate of decay is linearly proportional to the number of nuclides avaliable'. i.e dN/dt=-aN (a>0) How correct is this law? Are there better models of describing nuclear decay? If so what are they?

This may be better suited for the nuclear engineering forum, so feel free to move it. In decay processes that involve beta decay (or positron decay), there are pure beta emitters and mixed beta/gamma emitters. What determines whether a specific nuclide is just a pure emitter as opposed to a mixed?

The question is: Assume an atom just became Lead-206--why would such an assumption be important?--when it was orginally Uranium-238. Show all the steps it took to get from 238U to 206Pb. For each step, indicate the nature of the decay. Assume also that it spent exactly 1 half-life as each of...