3497 Shares

What happens to the rate of radioactive decay as the mass of radioactive material decreases?

What happens to the rate of radioactive decay as the mass of radioactive material decreases? Topic: In over your head homework
June 16, 2019 / By Maddox
Question: This was for this lab: http://www.evanschemistrycorner.com/Labs/Nuclear/L12-1a_Simulating_Half_Life.pdf and I completed the whole thing, and now I'm having trouble with the conclusion questions. The whole concept of the lab kinda went right over my head. Can you please help, particularly numbers 3 and 4? I'm not looking for a cop out of homework, this is me genuinely struggling with this concept. Thanks.
Best Answer

Best Answers: What happens to the rate of radioactive decay as the mass of radioactive material decreases?

Jehosaphat Jehosaphat | 6 days ago
"3.Why is each toss in this simulation called a half life?" The probability for a coin showing head up or tail up is p=1/2. In the first trial one expects 50% of 50 pennies= 25 pennies to be decayed. Next, with 25 pennies, 12.5 pennies should have been decayed. In the third run 6.25 pennies are expected to have been decayed.. The key number of this simulation is 2 and because the number of pennies are halved by each run the "time" elapsed is a half life. "4. What is happening to the simulated rate of decay as the number of pennies decreases?" rate= -ΔN/Δt = (N₀-N) /Δt.. Now let Δt be the time of a run= constant. and set it 1 sec for convenience. Run.___.N₀__________.N ____.rate 1_______50__________25_____25 2_______25__________12.5___12.5. and so on. You see the rate is decreasing "5.What happens to the rate of radioactive decay as the mass of radioactive material decreases?" Since mass is proportional to mole ( 1/M) results from question 4 can be taken in to consideration: rate decreases until it becomes zero because no radioactive material is left over. "6.In what way does the data gathered during this investigation simulate the nature of half life?" In a stochastic process.
👍 180 | 👎 6
Did you like the answer? What happens to the rate of radioactive decay as the mass of radioactive material decreases? Share with your friends

We found more questions related to the topic: In over your head homework


Jehosaphat Originally Answered: How do creationists get past dating by radioactive decay?
Creationists get past radioactive dating by going on non-radioactive dates. I know, I know, but there's little more logic to it than that. These are people who, after all, decry carbon 14 dating as being totally inaccurate because "we've dated live snails and seals to be thousands of years old"-- something actual scientists call the reservoir effect and take into account when using carbon dating-- but then turn around in the very next breath and claim carbon 14 dating proves the Earth is young because you can find coal deposits with significant amounts of carbon 14 in them, and it shouldn't be there if the Earth was very old. That effectively makes their position on carbon dating "you can't trust carbon dating because it's totally unreliable, but I can prove the world is young because carbon dating says so". They also try to further impugn the method by claiming the Earth's atmosphere should reach a point of equilibrium in how much carbon 14 it contains, and then assert that process would only take 30,000 years and we haven't reached it yet, so obviously the Earth is less than 30,000 years old. As for other forms of radioactive dating, they usually get around the validity of it by one of two methods. As you mentioned, they usually claim we're just assuming radioactive decay proceeded at the same rate in the past as it does today, so really we have no way of knowing for sure whether those dating methods are accurate. They often couple that with claim the only reason we have any idea how fast those atoms decay is because of the geological layer in which we found whatever it is we're testing, and we only assume that geological layer was laid down X number of years ago because we arbitrarily decided it was, so we "calibrate" radiometric testing to give us the result we want to see. Or in other words, they think radiometric dating works like this: "I want to believe this geological layer is a hundred million years old. I've dug up this fossil and will date it to prove the geological layer is a hundred million years old. Now I'll change the results of the test until they say the fossil is a hundred million years old. Hey! The fossil dates to a hundred million years ago, so that proves that geological layer is a hundred million years old. I'll just assume everything else I find in that layer is also a hundred million years old and keep adjusting my results so I keep getting that number!" It's very difficult to explain to people whose understanding of just how science works is so woefully off base, and who more to the point think you are trying to intentionally deceive them and hide the truth, that it doesn't work the way they think. * * * To address a couple of the issues I raised above (before a Creationist pounces on them)... Coal deposits in which high levels of carbon 14 are found are always located near veins of radioactive minerals, most often uranium deposits. We know that as the uranium decays, the radiation from it will cause some of the material in nearby coal deposits to convert to radioactive carbon 14, so it isn't a mystery to us why those deposits yield a false date, and geologists know perfectly well not to use carbon dating in such cases because the sample is known to have been contaminated. On the subject of equilibrium, while it is true the level of carbon 14 in the Earth's atmosphere is not in equilibrium, that does not prove the Earth is less than 30,000 years old because the 30,000 year calculation assumes the processes which produce atmospheric carbon 14 occur at a constant rate, and we know they do not. The strength of Solar activity that bombards the Earth with the radiation necessary to produce carbon 14 is not constant, nor is the ability of the Earth's magnetic field to deflect a given portion of the radiation. So we know our atmosphere will never reach a true "equilibrium" when it comes to its carbon 14 content. And lastly, we do not base our dating methods on such unfounded, cyclical assumptions, but it's a very long explanation on that one, so I will simply refer to a page that explains it in more detail: http://www.talkorigins.org/faqs/dating.h...
Jehosaphat Originally Answered: How do creationists get past dating by radioactive decay?
Australia and Canada would be glowing masses too. Miller, the only mistakes in C-14 testing are caused by the reservoir effect, (look it up). Deceitful creationists use this as an excuse for discrediting radiometric testing without mentioning the reservoir effect. And the decay of radioactive material like uranium is a basic natural process and unless the physical laws of the universe keep changing the decay rate will remain constant.
Jehosaphat Originally Answered: How do creationists get past dating by radioactive decay?
well I can't give you a definite answer, but I can give you a popular belief. One belief is that just as God created Adam and Eve at about 25 - 30 years old, he also made the rest of His creation already aged. Example, on the day He created trees, if you went and checked one, you would say, this tree is about 40 years old.. but He had just created it that day. Couldn't the whole earth be that way? But let me ask you a question, we know the sun is slowly burning down, and that now it is much smaller than it was before, so if our galaxy is billions of years old, how big was the sun billions of years ago? ..probably so big that no planets could exist in this galaxy, never mind a planet like earth that suppots life.
Jehosaphat Originally Answered: How do creationists get past dating by radioactive decay?
They jump on the fact that science is continually adjusting and improving the validity of its measurements. They take these minor changes to be a weakness whereas a normal person sees it as a strength.

Jehosaphat Originally Answered: Is Hiroshima and Nagasaki still radioactive?
The radiation itself was momentary however the neutron burst would've activated and debris into their radioactive isotopes with varying half lifes. Some of these isotopes are particularly dangerous as they are variations of elements our body naturally uses so the isotopes are brought into close proximity with our DNA causing damage. This is why iodine tablets were part of the "survival kit", by being saturated with known iodine, you would not absorb the radioactive iodine and it would not come into close enough proximity to harm you. Most of the other elements are easily filtered out and kept at a safe distance with simple barriers and air gaps. Iodine-131 has a half life of 8 days so it's only a problem for a few months at the most. Other isotopes like Thorium-232 have a half life of 14 billion years but fortunately these heavier elements are not the majority of the radioactive fallout, remember, the heavier elements must be in the debris in order to be activated into isotopes by the neutron burst and these elements only exist in trace amounts to begin with. There will always be residual radioactivity but the majority drops off quickly after the event. Yes, both Hiroshima and Nagasaki are still radioactive but no, it's not dangerous to be a tourist there as the bioavailable isotopes had very short half lives. It's often believed that the bombs were air detonated to maximize the area affected but that was not the case. An airburst minimizes the amount of debris drawn into the fireball and hence minimizes the radioactive fallout. Remember, they were anticipating putting soldiers at ground zero within days of atomic blasts. Note, the legs of your kitchen table are probably radioactive too. Ever since X-ray machines and smoke detectors have been scrapped, various radioactive materials have made it's way into the recycled metal to the point where virtually all refined metals are now radioactive. To make an accurate and sensitive geiger counter now requires salvaging metal from a WWII shipwreck.
Jehosaphat Originally Answered: Is Hiroshima and Nagasaki still radioactive?
This Site Might Help You. RE: Is Hiroshima and Nagasaki still radioactive? I heard nuclear waste has a half life of 1000 years or something like that. So does that mean those cities are radioactive.
Jehosaphat Originally Answered: Is Hiroshima and Nagasaki still radioactive?
Hiroshima and Nagasaki bombings were deliberate acts so they probably should not be considered "disasters". They should be considered extremely important events, as it marked the first two (and so far ONLY two) times that nuclear weapons were used in a war. Most people don't think of WWII as a "nuclear" war, but it was... at the end.

If you have your own answer to the question in over your head homework, then you can write your own version, using the form below for an extended answer.