Radioactive decay Definition and 216 Threads

Homework Statement Suppose that you wish to find out how much gasoline is in an underground storage tank. You pour in one gallon of gasoline that contains some half-life radioactive material that causes a Geiger constant to register 48400 counts per minute above background radiation. The next...

Hello, I am trying to simulate the gammas from certain radioactive decays but I am really puzzle as to how to approach this. The site I'm using as a reference lists the intensities of the different gammas corresponding to an specific decay. The thing that confuses me is that, for example...

Homework Statement After 25 years, 60% of a radioactive material decays. What is the half-life? Homework Equations I used a ratio of 25/.60= x/.50 The Attempt at a Solution I also tried this ratio as 25/.40= x/.50 I am not really sure what equation I should be using but this...

Do ions have a measurably different rate then their neutral counterpart or does the rate of radioactive decay and electrons have no correlation? Also, when a source states an elements half life is that the same for all of its isotopes?

Homework Statement The edge of a nucleus can be roughly modeled as a square potential barrier. An alpha particle in an unstable nucleus can be modeled as a particle with a specific energy, bouncing back and forth between these square potential barrier. Consider a nucleus of radius r and an...

I don't have much of a scientific background, but I am interested in learning about geology. More specifically I would like to study the nature of igneous rocks, particularly their formation through volcanic processes. I'm also very much interested in understanding how the process of...

According to my textbook, the decay constant is the probability that a radionuclide will decay in any second (hence the unit s^-1) and so the total number of radionuclides decaying at any second, i.e. the activity, is λN but this is also the rate of change of N thus dN/dt = -λN Surely...

Homework Statement This problem involves calculating the age of plant material from which 3 radioactive disintergrations per minute per gram of carbon are detected. During its lifetime, the plant took in carbon from the atmosphere. Of this carbon, for every 1012 atoms of normal 14C, there was...

Homework Statement Homework Equations N=N0e-λt The Attempt at a Solution I can do all of part (a) but I'm stuck on part (b). I don't even know where to begin. I just have no idea what to make of this question. Could someone prod me in the right direction ?

I am not quite sure why there are only four types of decays, alpha, beta plus and minus, and electron capture. I know that heavy nuclides undergo alpha decay because it is a fast way to loose 2 protons and 2 neutrons, also that the alpha particle is very stable. For beta plus and minus...

I don't understand where radioactive decay comes from. Everything I've read discusses how the environment can influence the decay (for example, neutrons in different nuclei decay with different speeds), but I couldn't find an explanation of what is the underlying cause of the decay. If the...

Homework Statement Given the followin[Sg decay chain- X→Y→Z Solve for Nx(t), Ny(t), Nz(t) for the case of Rx(t)=\alphat and assuming Ny(t)=Nz(t)=0 Homework Equations dNx(t)/dt = -\lambdaxNx(t) + Rx(t) dNy(t)/dt = -\lambdayNy(t) +\lambdaxNx(t) dNz(t)/dt = -\lambdazNz(t) +\lambdayNy(t) The...

(original question) Does the electric charge of an isolated block of radioactive material increase, assume that all emissions are reabsorbed? Subsequent edit: I guess if the body were isolated and emissions escaped the body, a charge would build up until the capacitance of the body is...

dHomework Statement the half life of U234 is 245.5 years. It decays by α emmission to Th230 whos half life is 75.38. there are 10^6 atoms of U234 and 0 atoms of Th230 at t=0. At what time will the number of atoms of each type be equal? the half life of U234 is 245.5 years and half life of...

Hi, Explain in terms of the number of nucleons and the forces between them, why argon-36 is stable and argon-39 is radioactive. My first doubt regards the number of nucleons. If a nucleon is the collective number of neutrons and protons, if we take carbon 12 for example, does it have 6 or...

Homework Statement I learned that radio-decay is exponential; say if A decays to B with constant y1 and B decays to C with constant y2 and C is stable, N1 is nuclei in A while N2 is nuclei in B. N1 = N0e-y1(t) Homework Equations Then, I tried writing the decay equation for B, and hit...

The fact that radioactive decay and continuous compound interest end up with the same formula (with the "rate" being negative in the former and positive in the latter) seems to me to be more a result of the ubiquity of the exponential function in solving differential equations than any common...

I am wondering what any experts think about these Wikipedia explanations of radioactive decay. (Wiki asks for help improving this article, so somebody must recognize some issues.) Thanks. under "EXPLANATION": Huh?? Does this mean anything?? What does "activation energy"...

Could you make a solar sail that derives it's energy from the decay of a radioactive element such as plutonium, uranium, or palonium? I understand that such elements radiate in all directions but if you had a 1 kg sphere of it attached to a boon which was attached to a reflective sail (e.g...

Does time dilation effect radioactive decay? For example, if I speed a radioactive atom up to near light speeds, will its decay slow? If so, could this be used to study atoms with a very short decay time?

I saw references on the web to periodicities in radioactive decay that are hypothesized to correspond to the varying levels of neutrinos emanating from the sun. How do neutrinos affect radioactive decay?

Ok, so all elements undergo radioactive decay. But why? I have been snooping around and what i find is that radioactive decay occurs because of instability of the atom nucleus in quantity, proton-neutron ratio and energy content; therefore we have alpha, beta and gamma decay consecutively...

Homework Statement I have some data for "Activity(Bq * 10^4)" and "time". I have already found the half life and everything but I can't seem to see any sources of error in the data Homework Equations I need sources of error. The Attempt at a Solution I said, the half life matches the...

What does "Activity" mean in terms of radioactive decay? I came across this term "activity" in text regarding radioactive decay and half lives. It is defined as "number of nuclei in a sample that decay within a given time." That definition if fine but then when presented in a graph life...

So... I know that decay occurs when the nucleus of an atom has an unstable proton-neutron configuration. My question is, at the instant that decay occurs, what triggers it? Is it quantum mechanical in nature? If so, why are half lives so consistent?

Homework Statement The technique known as potassium-argon dating is used to date old lava flows. The potassium isotope 40K has a 1.28 billion year half-life and is naturally present as very low levels. 40K decays by beta emission into 40Ar. Argon is a gas, and there is no argon in flowing...

For the basic model for exponential decay, there is a decay constant, which is related to the half-life. The decay constant multiplied by the number of particles should give the decay rate per second (activity). However, the model I want is for small periods of time. For a small enough period of...

Homework Statement I hope that I'm posting it in the right section... I did an experiment in class using a Geiger-Muller counter with the objective to find the amount of counts (how many photons hit the detector) due to natural radioactivity around my work station. I recorded 45 values of...

Homework Statement It is found that when a 6.3 x 10–5 g sample of radium-226 is placed in a vacuum and exposed to a screen of area 1.0 mm2 placed 1.5 m away from the sample, an average of 46 α-particles hit the screen in 10.0 minutes. Calculate the total number of decays per gram of...

hello! i'm planning to build such a generator, but i have some questions: 1. what dimensions and materials are needed to shield one typical geiger-muller tube from the background radiation? 2. even with the complete protection, is it possible that the counter tube will trigger without...

Homework Statement I am looking for some guidance on how to tackle the following problem. Maybe I am a little confused as it is rather wordy. It is known that an isotope, X, spontaneously decays by positron emission into another isotope, Y, with a half life of 100 minutes. The isotope X...

Homework Statement A radioactive nucleus can decay by two different processes. The half life for the first processes is t_{1} and that for the second is t_{2}. Show that the effective half life t of the nucleus is given by \frac{1}{t}=\frac{1}{t_{1}}+\frac{1}{t_{2}}Homework Equations...

Homework Statement You have two samples that exhibit radioactive decay. The first gives you initially a 1000/s decay rate and after one hour a 500/s decay rate. The second gives you initially a 500/s decay rate and after one hour a 250/s decay rate. Which sample has a higher probability per...

Homework Statement A sample of pure 99mTc is obtained and has an activity of 5000MBq. What will be the approximate change in mass of this sample after it has all decayed to 99Tc (assume no further decay from this state). (Avogadro's number = 6.023x1023 per mole; Half life of 99mTc = 6Hrs...

I have been trying for quite some while but I can't seem to get this problem off the ground.1)Suppose that you hydrolyze 4.644 grams of a protein to form a mixture of different amino acids. To this is added a 2.80 mg sample of 14C-labeled threonine (one of the amino acids present).The activity...

Homework Statement c) In 420 days, the activity of a sample of polonium, Po, fell to one-eighth of its initial value. i) Calculate the half-life of polonium. Homework Equations The Attempt at a Solution if the activity fell by 1/8 then it went through 4 half liefs (1/2*4=1/8) so...

Homework Statement complete the following decay equations by inserting the missing particle or nuclide information. Identify each type of decay. see attached screenshot please. Homework Equations The Attempt at a Solution I've done all of the decays but we have to label them and...

Homework Statement Complete the following decay equations by inserting the missing particle or nuclide information. Identify each type of decay. i) 90?Sr = ?39Y + ? + ? ii) 22?Na = ??Ne + β+ + ? + energy iii)24294Pu = ??? + alpha + ? iv) 235?U =...

How can we prove that the mean life time of a radioactive decay is reciprocal to the decay constant?

http://www.symmetrymagazine.org/breaking/2010/08/23/the-strange-case-of-solar-flares-and-radioactive-elements/" I just read this article. It suggests that solar activity has been shown to affect the rate of nuclear decay in the lab and that a particle may be responsible. Is this new information...

How are Madame Curie's notebooks still radioactively dangerous when Hiroshima is not?

Homework Statement Nitrogen in the upper atmostphere is convereted by radiation to carbon 14 the half-life of carbon, \tau = 5730 years carbon 14 makes up a known proportion of living plants and animals, after they die, the proportion of carbon 14 decays. - History records that an eruption...

Since it is deterministic, the deBroglie-Bohm theory needs a model, mechanism or story whereby complete information of the pilot wave, particle trajectories and other hidden variables will allow calculation of the decay time of a particular unstable atom. What progress has been made on this...

Homework Statement Ra (mass number 226 atomic number 88) undergoes alpha decay to form radon. If the mass of a radium nucleus is 3.753152x10-25kg, the mass of the radon nucleus is 3.686602x10-25kg and the mass of the alpha particle is 6.646322x10-27kg, find the energy released in the alpha...

I've been working with this problem for almost two weeks trying to find a good equation for the decay of Bismuth to no avail. Can someone give me insightful comments: Here's the problem: Homework Statement In the radioactive decay series of Uranium (238, 92), isotopes of lead...

If isotope A decays to isotope B. Does it mean that if within 1 hour we have 10 mg of A that decays, do we get exactly 10 mg of B after one hour? thanks

Homework Statement {}^{241}_{95}Am produces \alpha particles, which interact with {}_{4}^{9} Be to produce neutrons. The Am sample emits \alpha particles at a rate of 70.0s^{-1} on June 16, 1996. What was the activity on June 16, 2004? Homework Equations The half life for...

Homework Statement A radioactive sample contains 3.25 1018 atoms of a nuclide that decays at a rate of 3.4 1013 disintegrations per 26 min. (a) What percentage of the nuclide will have decayed after 159 d? % (b) How many atoms of the nuclide will remain in the sample? atoms (c) What is...

Hello; Just needed to clarify something. When anti-particles undergo gamma radioactive decay, is a gamma ray produced, or an anti-gamma ray? Or something completely different? Thanks.

Hello; I remember being taught long ago that radioactive decay is random, but, no one ever explained to me why. Surely there has to be a reason for it? Or is it simply the case of it not being random? (particles in gases don't move randomly, it is dependent on various factors) Thanks.