Half-life Definition and 130 Threads

Hello, I have a relatively simple question. I'm just wondering, with half-life problems, how could I solve something like the following: Isotope: 226Ra Half-life: 1620 years. Initial Quantity: X (Solve for this) Amount after 1000 years: 1.5g Where I'm supposed to find the initial...

Question: The half-life of tritium (hydrogen-3) is 12.3 yr. If 46.9 mg of tritium is released from a nuclear power plant during the course of an accident, what mass of this nuclide will remain after 24.6 yr? (Significant figures are important) My answer: 11.7 mg. I came to this answer by...

Homework Statement The half-life of iodine-131, an isotope used in the treatment of thyroid disorders, is 8.04 d. (a) If a sample of iodine-131 contains 8.5 1016 nuclei, what is the activity of the sample? Express your answer in curies. (b) If the half-life of iodine-131 were only one-fourth...

In the 16th edition of the chart of nuclides, it lists Cu-64 as decaying to Zn-64 by beta minus decay. OK, no problem here. Then it lists Zn-64 decaying back to Cu-64 by positron decay with a half life of 1.1 x 10^19 years. Assuming this isn't some typo, I have 2 questions. 1) How in blazes did...

(a) The half-life of radium-226 is 1620 years. Write a formula for the quantity, Q, of radium left after t years, if the initial quantity is Q0. Check me on this one: Q = (Q0 / 2(1620/t)) (b) What percentage of the original amount of radium is left after 500 years? Check this one as...

I have an assignment for which I need the half-life of about 30 nuclei that decay through spontaneous fission. The total half-life is easy to find, but I need the half-life for spontaneous emission only. Does anyone know where I can find this? thanks, Levi

Element A has a half-life of T_{1} and decays into element B, which has a half-life of T_{2} , while T_{2}<T_{1} . When is the mass of element B the greatest? (i.e. after how many doublings?) I have been trying to derive a formula to calculate this, but have so far been unsuccessful.

Something has a half-life of 18.4 days. How much time will a 50-mg sample take to decompose to 10 mg? My steps 50(1/2)^n/18.4 = 10(1/2)^n/18.4 25^n/18.4 = 5^n/18.4 (5^2)^n/18.4 = 5^n/18.4 5^2n/18.4 = 5^n/18.4 Exponent view 2n/18.4 = n/18.4 2n-n = 18.4/18.4 n=1 Am i doing...

Hey, I have been set this question as an assignment and I spent about an hour researching it yesterday and came up with what I thought was the right answer, but it has turned out to be wrong. "A theory of astrophysics proposes that all the elements heavier than iron are formed in supernova...

Is it possible to identify such an isotope? What are my choices if I wanted such a long half-life product. (Ultimately, I need it to activate a timing switch...!) :smile: Thanks, anyone for any pointers. AA

how can we fnd out the half life of sum element?

Q. A sample of a certain element with two naturally occurring isotopes becomes activated by neutron capture. After 1 hour in the reactor, it is placed in a counting room, in which the total number of decays in 1 hour is recorded at daily intervals. A summary of the recorded data appears...

"A radioactive substance has a half-life of 5 days, initial mass of 12kg. How much the original isotope will remain after 10 days?" This is just an example, the question itself is not important, i just want to know how to solve this type of problems generally.. thank you!

A substance decays from 20g to 15g in 7h.Determine the half-life of the substance. I know that: M=M_{o}\left\frac{1}{2}\right^\frac{t}{h}

As the temperature increases and pressure remaining constant. Does the half-life of a radioactive element stay the same? Also, Which gaseous radioactive waste product that is released into the atmosphere after it has decayed to a safe radiation level? radon-222, radium-226, cesium-137...

is it as interesting as Doom 3? actually, playing games is fun, but too time-consuming

I've got a question regarding half-life. Half-life is the time taken when the mass or countrate emitted of a radioactive sample drops to half. But if say, if a sample of 400 particular radioactive nuclides which go through radioactive decay. Won't the count rate reach 0 eventually, after...

An archaeologist digs up a piece of wood believed to be an ax handle from a dig. The wood is from an ash tree. The beta emission from the old piece of wood is 4 beta/min. A similar piece of wood that is freshly cut registers beta emission at 16 beta/min. The half-life of carbon-14 is 5,370 yrs...

Hi! I'd like to make some half-life measurements on water based foams. I have only simple instruments for it. Can anybody help me? I don't know the exact method that how to make this measurement correctly. And I also need the mathematical apparatus for it. Thanks a lot in advance!

I am new to this matter, but I was reading a problem about how as the muon travels at .98c, that it's half life is increased by an approximate factor of 5. What I have trouble with is when using the Lorentz transform, why time dilation is calculated in the moving system at the same X and V...

Radon-222 is a radioactive gas with a half-life of 3.82 days. A gas sample contains 4.5*10^8 radon atoms initially. Estimate how many radon atoms will remain after 12 days. This Is what i have done: 3.82 days=3.82*24*60*60=330048seconds what's next?

I was wondering if there were any known solid elements, natural or synthetic, which radioactively decay into a gas. It would be cool to watch a block of it become more and more sponge-like, and therefore less dense, as it decayed - structurally crumbling until finally no solid could be...

I was looking at a http://chemlab.pc.maricopa.edu/periodic/isotopes.html and was wondering why the half-life was sometimes replaced with electron volts? There's an example from the table below: Helium-6 806.7 milliseconds -> Lithium-6 Helium-7 160 KEV -> Helium-6...

After 3 days a sample of radon-222 decayed to 58% of its original amount: a) what is the half-life of radon-222? b) how long would it take the sample to decay to 10% of its original amount? check my answers please: a) m(t)=mo*e^kt t = 3 and m(t)=.58mo 0.58mo = mo*e^3k ln(.58)...

Lets say we have a radioactive element X in a closed environment, if we were to measure the half-life of element X's radioactive decay at: 1) Near absolute zero 2) At room temperature 3) At 1000s of degrees Kelvin Would there be a change in element X's half-life even if it is minute? And...

The book we are using (Physics 101) has shown quit well that there will be a greater quantity of heat loss (and faster), of a substance to it’s environment, if the difference of temperatures between the two is greater. Also, there will be initially a faster rate of heat loss / time...

Well, hi guys, I know I am new to this forum and all but I am having a mental block with one of my physics questions. My teacher gave me this "mind-buster" question, and I want to solve it. Can give me some help or hints on how to go about solving it. I don't need the answer to it, i just need...

1000 particles of an unknown radioisotope decays to 472.37 particles in 50 days. (a) What is the half-life of this substance? Any problems that I had done previously, the half-life was given. Any help will be greatly appreciated. Well, I know a few things, but don't know if they...

Greetings ! I'd like to ask a few questions about half-life (not the PC game :wink:) functions: 1. Are they of the same shape for all nuclear particle decay reactions currently known and observed ? 2. What is the function mathematicly (and it's relevant shape of course) ? 3. What...

Do protons decay or are they completely stable? If they do then what is their half-life?