Decay Definition and 998 Threads

the half life of C14 is 5730 years. if a sample of C14 has a mass of 20 micrograms at time t = 0, how much is left after 2000 years? I learned from somewhere that these exponential decay and half life problems use the equation y = ab^t or y = a(1+r)^t where y = total, a = initial...

Decay Constant, as it says on my revision sheet is defined as 'The probability of a nucleus decaying per unit time'. Does it mean that it can't be greater than 1? Otherwise, doesn't that imply that a nucleus is most certainly going to decay(greater than 100% chance within a certain period...

Homework Statement The nuclide (32,15)P undergoes Beta - decay with a half-life of 14.3 d. It is used as a tracer isotope in biochemical analysis. What is the initial decay rate of a 1.2mg sample? Homework Equations T1/2 = Ln 2 / λ Ro = λN0 The Attempt at a Solution I first...

In β+ decay a proton releases a positron and an electron neutrino causing the proton to change into a neutron to help balance the nucleus. I am studying advanced PET imaging and trying find a better understanding of the positrons other half. Does it just go on being a normal electron.

Homework Statement An old wooden tool, containing 75.0 grams of carbon, is found in an ancient tomb. The tool emits 500 electrons/minute from the beta decay of 146C. How old is the wood from which the tool was constructed? Given: The half-life of 146C is 5730 years, the ratio of 146C to 126C in...

The neutral phi meson decays to make two photons after around 8 x10-17 seconds Is this just straight annihilation of the quark anti quark pair? If it is this does it take this amount of time due the quark colour, as in do you need a red up and a red anti up for annihilation? Or does this...

Homework Statement What is the mass difference of the following process: 13N → 13C + e+ + veHomework Equations Δm = m(A,Z) - m(A, Z-1) - m(e+) Neutrino has negligible mass. Z proton number A = N + Z, where N is number of neutrons The Attempt at a Solution \begin{align} \Delta m &= m(^{13}N)...

Homework Statement Why is D*+(2010) → D+(1869)π0 allowed via the strong interaction but Ds*+(2110) → Ds+(1969)π0 forbidden. The numbers in the brackets are masses in MeV. Homework Equations The Attempt at a Solution My guess was that mass was not conserved, but if π0 is 135 MeV...

Any help is appreciated, thanks. Homework Statement In my course of differentials equations we were given the task to model a real life system with them, we choosed something that resembles a pendulum.Homework Equations The Attempt at a Solution We went to the lab and got experimental data from...

Homework Statement Which of the folowing decays are forbidden by C-iinvariance ω° = π° + γ η' = ρ° + γ π° = γ +γ + γ Homework Equations None The Attempt at a Solution The answers are meant to be: ω° = π° + γ -1 : (+1) (-1) -> Allowed η' = ρ° + γ +1 -> (-1) (-1) ->...

I fully understand mathematically using differential equations and also using conservation of energy why current should decay in an RL circuit. However , I cannot comprehend how this phenomenon can be explained purely based on induced voltages and currents. An intuitive understanding basically...

Radioactive decay of granite ---> How many years does it take? Homework Statement Radioactive decay of granite and other rocks in the Earth's interior provides sufficient energy to keep the interior molten, to heat lava and to provide warmth to hot springs. This is due to the average release...

Hi folks could someone please check my calculations contained in attached file? thanks. (incidentally, how can i create a link to such files in the future, weaving them into my text?) Deus(has gone)

Homework Statement A particle X with rest mass mx is traveling with speed vx = 0.8c along the x-axis in the lab frame. (a) Write down the four-vector momentum of the particle in the lab frame in terms of vx and mx. The particle decays to two particles, A and B, each with mass mx/4...

The radioisotope 40K decays either by electron capture (~10% of the time), releasing about 1.31 MeV, or by beta decay (90% of the time), releasing about 1.51 MeV. Thus the mean heat released is about 1.33 MeV per decay. There are 1.5x10^25 40K atoms in 1 kilogram. Therefore the energy which...

Homework Statement The amount (A) of cesium-137 remaining after t years is given by A=A_{0}*2^{\frac{-t}{30.3}} where A_{0} is the initial amount. In what year will the cesium-137 be 10% of that which was released at the Chernobyl disaster in 1986? Homework Equations...

Homework Statement The half life of a particular isotope is 10.84 days. Find the number of atoms of this isotope that would be necessary to produce a sample with an activity of 1.79 micro-Ci. Homework Equations R=N_{0} \lambda e^{-\lambda t} where R is the decay rate lambda is the decay...

Homework Statement Consider a nucleus which is initially at rest and in an excited state with energy Ei. It then decays to a lower energy state with energy Ef by emitting a gamma-ray photon. Show that the energy of the photon is approximately given by Eγ≈ΔE−(ΔE)^2/(2mc^2) where ΔE = Ei - Ef...

Could someone please tell me what the symbols in the Zee.csv file mean on the CERN webpage (https://cms-docdb.cern.ch/cgi-bin/PublicDocDB/ShowDocument?docid=11581)? I am doing a project for my statistics class and that information would be useful. I'll appreciate any and all help.

Hi all, Has anyone know how to calculate the loop function of Higgs decay to photons/ gluons by t quark , or a useful reference. Cheers, Safinaz

Homework Statement A lambda particle decays into a proton (at rest) and a pion. The rest masses are: lambda: 1116 MeV/c^2 pion: 140 MeV/c^2 proton: 938 MeV/c^2 we want to find the energy of the a) pion b) lambda (before decay) Homework Equations I am assuming we need to use the...

Hello to all, i need more details about followings problems: Why nuclear spent fuel ponds must be cooling down and which is maximum allowable temperature in cooling agent? How we can evaluate decay power using theoretical formula?

Homework Statement A nuclei of a atomic number Z decays into a alpha particle (a He nucleus with Z =2) and a daughter nucleus with (Z_{d}). The decay may be described as the tunneling of an alpha-particle through a barrier caused by the Coulomb potential between the daughter and the...

Homework Statement A body is found at 2:00pm at a temperature of 26°C, with a surrounding temperature of 18°C. Two hours later the temperature of the body is 21°C, when did the body die? T=Ae^(kt)+Ts where T is the temperature of the body A is the initial temperature k is a constant t...

This isn't a direct question and answer problem, it relates to an essay I am doing. I am a bit confused on the equations given by my tutor for radioactive decay, I suspect there is a mix up of symbols used where two symbols are used for the same think (such as N and R for the normal force). On...

Hi, so we are studying quantum physics at college and I just want to understand this concept of decay. Please could someone help me?

what are standards model limits on decay of K0, Do, B0 meson into a pair of neutrino and anti neutrino. I know that these highly suppressed due to involve FCNC. but if someone can tell me about theoretical limits on these reactions.

Radioactive Decay Probability? Say you are counting the number of decays and the time of observation is varied. I know that as time increases, the Gaussian Distribution becomes a closer fit to the observed probability than when the time interval takes smaller values because the mean count...

I was reading an article and it said that eventually, when you get silicon transistors to a certain size, they won't be able to operate anymore and will end up melting. I have always wondered the following... what is the point of trying to make transistors smaller when we can just make the...

Hi, I'm confused about a statement about the change in final/initial states of the daughter/parent atom in an alpha decay. It is the following; "The spin between the parent (I_i) and daughter (I_f) can change by lh (h being h-bar, l is the orbital angular quantum number of the alpha particle)...

I'm not a physics person (did not take it in high school), but I was wondering why the speed of light is the constant (in relativity) and not the half life of an electron or positron. The name of a good introductory book to physics would be good too. Thanks in advance.

What are the accepted numbers for the decay rate and lifetime of Z-> mu+mu- and Z-> e+e- decays? also what is the unit for the decay rate? thank you!

I ask this because I've heard repeatedly that all the equations in current physics models are reversible in time, save the second law of thermodynamics. But does this mean the process of radioactive decay is also reversible in time?

Homework Statement A nucleus contains Z protons that on average are uniformly distributed throughout a tiny sphere of radiues R. Suppose that in an accelerator experiment a positive pion is produced at rest at the center of a nucleus containing Z protons. The pion decays into a positive muon...

I would like to hear opinions on the variation in decay rates as described by Fischbach and coworkers and how (if at all) this will affect radioemtric dating. Does this phenomenon indeed exist or is it the result of errors in experimental technique?

Okay, this is a really simple question, so to anyone looking for some extraordinarily complex differential equation question turn away now, or be blinded by boredom. My query is rooted in a question I had about building a water clock... so seemingly relevant to Differentials, I know...

What are the thoughts about using a magnetic sail propelled by a powerful alpha emitter (e.g. polonium)? Imagine a 1kg sphere of polonium radiating alpha particles in all directions. Attached to the sphere, via boon, is a powerful magnetic field emitter that would repulse or even deflect forward...

Homework Statement The radioactive decay of a substance is proportional to the present amount of substance at any time t. If there was 15 grams at t=0 hours and 10 grams at t=3 hours. Set up the differential equation that models this decay and use the method of separation of variables to solve...

Homework Statement Radioactive decay is: N = N0e-λt N can also be used to describe count rate after a time, (t) where N0 is intial count rate and λ is decay constant... Half life, t1/2 od radioactive isotope is t1/2 = 1n2 λ The λ should be under the ln2 but it won't let...

Does the decay of B0 meson into two muons at the 3 ppb level, imply that this test for low-energy SUSY has failed?

Homework Statement A radioactive sample contains 2.25g of an isotope with a half-life of 3.8 days. How much of the isotope in grams will remain after 11.0 days? Homework Equations The Attempt at a Solution Hi! I've just started college this semester. I'm taking Introductory Chemistry. Right...

Homework Statement Explain why deuterium cannot undergo beta decay or produce a stable nucleus, while tritium can. Homework Equations n/a The Attempt at a Solution There was nothing in the lesson that really explained this, and the only reason I can find online is because deuterium...

Which of the following should occur at a greater rate: D0 to K(-) + (pi)(+) OR D0 to K(-) + positron + electron-flavor neutrino? I know that there are other decays that are Cabibbo supressed (or doubly so) but I can't see what would make one of these more likely than the other. Thanks

Can the rho(0) meson decay to a pion(0)+gamma ray? If so, which, between this decay and the decay to pion(+) + pion(-) dominates? I know decay modes will dominate as a result of the relative strength of fundamental forces involved, so what are the forces and their relative strengths in this...

why is that particles such as the tau muon have a short lifespan and why is it that particles decay into other partcles? furthermore, what are the process that occur in particle decay?

Homework Statement The initial amount of radioactive atoms on a sample of 24Na is 10^10. It's half-life corresponds to 15 hours. Give the amount of 24Na atoms that will disintegrate in 1 day.Homework Equations I started to solve it using the formula N=Initial Amount of Atoms /...

Hi. After Beta minus decay does the atom gain a charge and become an ion? I.e after a neutron become a proton and electron does the atom become positively charged because it has more protons than electrons? Or does it capture an electron from somewhere else? Thanks

Here is Abby's question: Here is a link to the original question: Differential Equations time constant problem? - Yahoo! Answers I have posted a link there to this topic so the OP can find my response.

I've just been really thrown off by what this problem is asking me. Given: The decay of a radioactive material may be modeled by assuming that the amount A(t) of material present (in grams) at time t (minutes) decays at a rate proportional to the amount present, that is dA/dt= -kA for some...

On decays I have only a preliminary understanding. I was looking up the half life of a neutron for another reason. The value I found for neutron decay for a free neutron was 10.3 seconds. Hope that's reasonably accurate. Anyways knowing that neutrons are stable in a nucleus held together...