Radioactive decay Definition and 212 Threads

I am confused about the half life and radioactive decay and how to figure out the problems. here is one from my book: A zircon sample contains 4000 atoms of the radioactive element 235U. Given that 235U has a half life of 700 million years, how long would it take to decay to 125 atoms?

Is radioactive decay dependant on temperature? what about pressure? my initial thinking is yes and no

Homework Statement in fortran 90 write a program to using the euler scheme to solve the differential equation for decay of a radioactive substance dx/dt = -j*x solving the equation we get x = e^(-j*t) following info is given 2. Homework Equations and values t0 = 0.0 tF =...

Homework Statement Suppose that a given radioactive element A decomposes into a second radioactive element B, and that B in turn decomposes into a third element C. The amount of A present is initially a0. The amounts of A and B present at a later time t are a and b respectively. If k1 and k2...

~Radioactive decay simulation Homework Statement i have modeled a simulation of radioactive decay and am using an exponential model of y = Ae^kx and I am asking to analyse my model and justify my choice of model. and points I can discuss are relating the solution to the problem and...

Can anyone tell me what makes an atom unstable, and more prone to radioactive decay? From what I've read in books and on http://en.wikipedia.org/wiki/Nuclear_decay" , it's caused by flucutations in the quantum vacuum which disturb the nucleus. But why are some atoms more prone to be bothered...

The problem states: I know it's beta decay, but there are two types of beta decay and I'm not sure how to tell which one would happen. If anyone is more familiar with these kinds of questions than I am, I'd be really thankful for any help. Thanks ahead of time!

Homework Statement A Uranium mine extracts sandstone in which the Uranium ore grade is 0.25%. Consideration is given to extracting Radium from the tailings. Estimate the concentration of Radium in the tailings and, using the data provided, determine if the proposal is financially viable...

Homework Statement A laboratory rat is exposed to an alpha-radiation source whose activity is 11.3 mCi. What is the activity of the radiation in disintegrations per second? in becquerels? The rat has a mass of 315 grams and is exposed to the radiation for 12.3 seconds, absorbing 39% of...

I have an essay on radioactive decay, here is the title 'Explore the nature of radioactive decay and Discuss it's applications' Does anyone know any good reference material for this kind of thing? Equivilence of mass and energy Alpha, Beta, Gamma Nuclear power Med Physics Carbon...

I was doing some research on Technetium and I found out that it occurs naturally in uraninite from the spontaneous fission of U-238. But on the decay chain of U-238 I can't find Tc any where... So what's the difference between spontaneous fission and radioactive decay?

Does the half life of a particular radioactive decay change if the sample is accelerated close to the speed of light ? Didn't Hawking answer that question in the 1980's ? Shouldn't the half life itself change over time ? (since the normal pdf is the one with the most entropy of information and...

This problem has always bugged me, and the only answers I've been given were on the lines of "meh". What I don't understand is that if we are given 1 gram of a radioactive substance with a half life of n years, why is it that after n years, the substance is reduced to 0.5 grams of radioactive...

how the decay depends on total mass of the radioactive element? is it necessary that all the atoms of the element keep contact among them, for the above case?

Homework Statement Analysis of the material shows that it contains both Gallium-64 (atomic mass = 63.936838u) and Zinc-64 (atomic mass = 63.929147u). Which nuclide is the parent nuclide and which is the daughter nuclide?Homework Equations N/AThe Attempt at a Solution The answer is supposed to...

Homework Statement Plutonium-238 with a half-life of 90 years, emits and alpha particle of energy 5.10 MeV. 180mg of this radioisotope is used to power a pacemaker. Calculate the initial power in mW, supplied by Plutonium-238, assuming a 100% efficiency for the conversion of decay energy into...

Homework Statement This particular exercise has no "problem statement" but I'll explain it in detail using all the information provided to me. The class was presented with a table of data containing values for time (in days) and activity (in cts/sec) for a radioactive isotope Iodine-131...

After asking my own question on half-lives and radioactive decay despite having read the library article on Radioactive Decay, I felt that I should post a less formal, more in-depth explanation of how to actually solve the equations. There are two primary equations that I use when dealing...

[Hey I have also been asked this question, A mouse dropping was found in a house in Ireland and had a 14C:12C ratio that was 57% of a modern day standard. Use this value to estimate the aprox date when the mouse visited the house? The half life of 14C is 5715 year I used the following...

If nucleus A decays to nucleus B in rate a, and B decays to C in rate b, and C is decaying at the rate c. To setup a model for that process, we start from A \frac{dA}{dt} = - a A(t) and for B, part for B is dying out from it's own decaying process but some amount of A will decay into...

Hi folks I was wondering if someone could please help me with the following: Is the explanation for radioactive decay (if it is not "induced") the increase in entropy, and is it true that an activation energy must be overcome (if so, does that mean that it is not possible for an unstable...

I apologize if this is posted in the wrong forum. this may not be calculus but i would appreciate any help solving this equation radioactive decay equation is N=N0e^-(0.693t/T(1/2)) N is the current specific activity value, N0 is the initial specific activity, t is the time or age of the...

Homework Statement Unobtainium is a radioactive (and fictional) element, with its rate of decay being proportional to the amount of Unobtainium, u' = −k u . The half-life of Unobtainium, in other words the time it takes for half the initial amount to decay, is 2.3 × 10^9 yr. (a) Find...

can help me with this question :S? If 70% of a radioactive substance remains after one year, find its half-life. and Strontium-90 is a radioactive isotope with a half-life of 29 years. If you begin with a sample of 800 units, how long will it take for the amount of radioactivity of the...

Since beta decay emissions are affected strongly by a magnetic field, I am wondering (asking) if there has been any investigation into an oscillating (reversing) magnetic field, applied to a test sample under pressure, inducing a beta decay in a test sample. TIA, Gordon

Hello, I'd like to know when the formula N(t)=N_0e^{-\lambda t} is not valid anymore. By that I mean... since N_0 is the number of atoms at time t=0 and N(t) is the number of atoms at time "t", we see that N(t) depends of N_0. Now my question is : how do you know how many atoms should we take...

Homework Statement *I'm only stuck on part c During the testing process for some pharmaceuticals, the drug is "tagged" with a radioactive material. This way researchers can determine if the pharmaceutical is going to other parts of the body than the intended target and what effect it has on...

One thing that is really confusing me is Beta Particles. This site states that Beta Particles are electrons that are shot out of the nucleus (atomic core) of an atom. http://home.clara.net/darvill/nucrad/morebeta.htm To rationalize this claim it states that a neutron will decay to a...

As I understand it, in all forms of radioactive decay, constrained by E=mc^2, a spontaneous breakdown of an element or isotope occurs: that is, a massive element (parent) decays to a less massive element, isotope or leptons [daughter(s)], plus a release of energy. However, in alpha decay, the...

Hi there, I was wondering if anyone could help me with this question ... "A device used in radiation therapy for cancer contains 0.50g of cobalt (60-Co-27). The half life of cobolt is 5.27 years. Determine the activity of the radioactive material." Working out: (To find the decay...

What lead them to use e and the natural log of 2 in the decay formula? A much simpler (to me at least) method would is: N=No*.5^(time/half life)

Homework Statement Thorium (with half-life T1/2 = 1.913 yr. and atomic mass 228.028715 u) undergoes alpha decay and produces radium (atomic mass 224.020186 u) as a daughter nucleus. (Assume the alpha particle has atomic mass 4.002603 u.) The energy released from the decay of 0.6 g of...

[SOLVED] Radioactivity and radioactive decay Homework Statement Thorium (with half-life T1/2 = 1.913 yr. and atomic mass 228.028715 u) undergoes alpha decay and produces radium (atomic mass 224.020186 u) as a daughter nucleus. (Assume the alpha particle has atomic mass 4.002603 u.) What...

[SOLVED] Radioactive decay. Is energy released? OPINION PLEASE! This is my last question in my last Physics exam! YES! I'M ALMOST DONE! :smile: I would just like your opinion on this question... My answer is Yes... But sometimes I think it should be NO because of the question's option for a No...

1. surface water contains enough tritium to show 5.5 decays events per minute per 100. g of water. Tritium has a half-life of 12.3 years. You are asked to check a vintage wine that is claimed to have been produced in 1946. How many decay events per minute should you expect to observe in 100.g of...

Homework Statement If A is the amount of radioactive material present at time t, A_0_ was the amount present at t=0, and h is the materials half-life, then A=A_0_ 2^-t/h Carbon-14 Dating: How old is a wooden statue that remains only one-third of its original carbon-14 content...

Homework Statement An element of atomic number 82 and mass number 214 decays radioactively to an element of atomic number 82 and mass number 210. Which of the following emissions achieve this result? Check all that apply. a. four beta particles b. two beta particles and one alpha...

Homework Statement Let's consider a radioactive decay according to the attached figure. A particle of initial mass M and charge Q is resting according to a referential R and disintegrates itself on 3 identical particles. As shown in the picture, 2 of the particles have known speeds 4c/5 and...

Total Frustration!Radioactive Decay!Need Fast Help! Hello, I have the link to the excercise: http://www.sciencecourseware.org/VirtualDating/files/RC_6.php" Here are my answers: 1. 1200 2. 2100 3.3800 4.14500 5.1125 6. 2050 7. ? I would think (7) would be 3775, but it's not...

[SOLVED] Radioactive decay Hi guys, this is just a basic maths incompetency. I hope someone can guide me forwards! (Slack biology student, delving into physics) I can do (a) with no problems, and thus I can probably do the latter half of (b) and (c) without issue. My stumbling point is...

I think there was a an error made in my physics book. It says alpha particles are fired at beyllium nuclei to induce the reaction Be He C + n Calculate the maximum kinetic energy of the neutron in MeV. Im guessing it means Be + He = C + n This makes the atomic numbers and mass numbers on...

[SOLVED] Radioactive decay. Given Ax, Ay and t½ for Y, get t½ for X. Not possible? Homework Statement This is from Advanced Physics by Adams & Allday, spread 8.13 Question 1. The activity of 20 g of element X is four times the activity of 10 g of element Y. Element Y has a half-life of...

Hello, Based on a starting isotope, isotope mass, and duration of time, what calculations would be used to find the mass remaining of each individual nuclide in the decay chain after the time period? I think that the rate at which the final product is formed depends most on the nuclide with...

Im not sure if this is a bad question but what is radioactive decay and why is it so important they needed a new force to explain it. It might just be me but compared to the other three forces its existence seems miniscule. (just turned 14 so am still in stupid integrated science for eighth graders)

I got some questions about radioactive decay: Do all atoms decay radioactive particles, only in a higher or lesser degree? I heard that atoms that have more protons (higher in the periodic system) than led, emit radioactive decay, and then stop at led. Does that mean that led does not emit...

What is the proper use and meaning of "Radioactive decay"? How much decay HAS occured This is a second thread to clarify my first thread about a debate with my biology teacher. I went back in an edited the content and title but it still posts under my original title anyway,,,, what...

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...