this is related to carbon decay .....(mathematics)  i need the answer quickly!?
925143
This is an exponential increase function so it has the form\n\nN(t) = N0 e^(- λ * t)\n\nwhere N is the number of infected, N0 is the initial number of people infected, λ is the decay rate and t is the amount of time.\n\nIt is given that N(0) = 1 person and N(3) = 25 people\n\nUsing these values we can solve this for λ. These two equations are\n\n1 person = (1 person) e^(- λ * 0)   [a]\n\nand\n\n25 people= (1 person) e^(- λ * 3)  [b]\n\nSolving [a] will not let us determine λ so we must use [b] to find it. Taking the natural log of both sides gives us\n\nln[(25 people)/(1 person)] = ln(e^(- 3 days * λ))\nln25 = -3 days * λ\n(ln25)/-3 days = λ\nλ = -1.07/day\n\nSince we used days to determine the 'decay' rate we must now convert one week to days. So one week is 7 days. Now to find the number of infected we just plug in the values into the formula to find N(7)\n\nN(7) = (1 person) e^[-(-1.07/day) * (7 days)]\n\nnotice here that the units in the exponential cancel out, as they must, so that out units for out answer is people, as we would expect.\n\nEvaluating this expression gives \n\nN(7) = (1 person) e^(7.51)\n= 1826.21 people\n\nSince there are only 500 people everyone is infected. Because you referenced carbon decay that is why I used an exponential function. I'm not sure if this is correct, but it's what I came up with. This seems to be a particularly nasty virus.
247742
The half time for decay of C14 is about the same as the biblically calculated age of the earth by change.\nThe decay time is constant and the age grows.\nThe margin is a couple of years, depending on the measured time. The longer you count the more precise the result.
630069
NaOH (Base) + HNO3 (Acid) -> NaNO3 (Salt) + H2O (Water)\n   H  H H\n   |  | |\nH-C-C-C-H\n   | | |\n   H H H\n\nReplace the last H by an -O-H\n\nDraw the carbon skeleton first.
414512
As soon as a living organism dies, it stops taking in new carbon. The ratio of carbon-12 to carbon-14 at the moment of death is the same as every other living thing, but the carbon-14 decays and is not replaced. The carbon-14 decays with its half-life of 5,700 years, while the amount of carbon-12 remains constant in the sample. By looking at the ratio of carbon-12 to carbon-14 in the sample and comparing it to the ratio in a living organism, it is possible to determine the age of a formerly living thing fairly precisely. \nA formula to calculate how old a sample is by carbon-14 dating is: \n\n\nt = [ ln (Nf/No) / (-0.693) ] x t1/2 \nwhere ln is the natural logarithm, Nf/No is the percent of carbon-14 in the sample compared to the amount in living tissue, and t1/2 is the half-life of carbon-14 (5,700 years). \n\nSo, if you had a fossil that had 10 percent carbon-14 compared to a living sample, then that fossil would be: \n\n\nt = [ ln (0.10) / (-0.693) ] x 5,700 years \nt = [ (-2.303) / (-0.693) ] x 5,700 years \n\nt = [ 3.323 ] x 5,700 years \n\nt = 18,940 years old \n\nBecause the half-life of carbon-14 is 5,700 years, it is only reliable for dating objects up to about 60,000 years old. However, the principle of carbon-14 dating applies to other isotopes as well. Potassium-40 is another radioactive element naturally found in your body and has a half-life of 1.3 billion years. Other useful radioisotopes for radioactive dating include Uranium -235 (half-life = 704 million years), Uranium -238 (half-life = 4.5 billion years), Thorium-232 (half-life = 14 billion years) and Rubidium-87 (half-life = 49 billion years).
564371
1. Because carbon-14 has a half-life of only 5,730 years.  So after 60,000 years there is not enough left to measure reliably.  That's why carbon dating is *not* used for fossils (despite what many people, including most creationists, think) ... there are dozens of other techniques used for dating fossils and rocks.\n\n2. Because it only works on things that were eating or breathing carbon ... i.e. things that were once alive.  (So it is useless for rocks, or asteroids, much less stars.)\n\n3. Because you actually need a sample of what you are dating ... so you could not use it to date things like distant stars or galaxies (the things that go back to the Big Bang).
376758
if you know the half life of 14C, then you can find how old it is by doing this.\n\nfirst setup the equation .5^x=.15\nso...ln(.15)/(ln(.5))=2.737, so it takes 2.737 half lives to get to 15% carbon.\n\nThe multiplay 2.737 by the half life and you done
869096
It is clearly true.\nThe halflife is the amount of time it takes for half of the atoms in a sample to decay. But it does not mean that the other half will be gone in the second period of time, only half of what is remaining.\nSo in 24,000 years you will have 1/2, in another 24,000 years you will have 1/2 of that, or 1/4. In another 24,000 years you will have half of that or 1/8. In another 24,000 years you will have 1/16, and when 100,000 years is past, you will have between 1/16 and 1/32 of the original amount.\n\nThe link has educational illustrations of the process.\n\n;-D It is better not to make any in the first place!
526116
Basically, all you need to know is the initial amount (8.0 grams I assume), and the half life (46 days).  Then you can build an exponential model of the form:\n\nA(t)=A*e^(k*t)  \nA is initial amount\nk is decay constant\nt is time\n\nKnowing that after 46 days, there will be half as much present:\n\n4=8*e^(k*46)\n\nThen solve for k using logarithms.  \n\nln(0.5)=46k\nk=ln(0.5)/46=-0.01507\n\nSubstitute into equation to get time dependent equation:\n\nA(t)=8*e^(-0.01507*t)\n\nNow you want to know how much is left after t=184:\n\nA(184)=8*e^(-0.01507*184)\n\nA(184)=0.5 [grams]\n\nViola....
1040448
ask your chem prof or tutor ..it's hard to explain over the internet!
496873
Sorry this is so long, but I have to first fix some misinformation given in other people's answers.  Specifically, carbon-14 (a.k.a. C14, carbon dating, or radiocarbon dating) is useful for dating a lot of things, but *not* fossils!  Instead, other forms of radiometric dating are used for fossils.  \n\nThe 'half-life' is a measure of how fast the process of radioactive decay causes one type of atom to decay into another type.  For example carbon-14 (C14) decays into nitrogen-14 (N14) with a half-life of 5,730 years.  This means that if you have a bone with 1 gram of C14, then after 5,730 years, 0.5 grams will have decayed to N14, leaving 0.5 grams of C14.  After another 5,730 years only 0.25 grams would remain.  And so on.\n\nNow, 5,730 years is not very long in geologic terms.  This means that after 50,000 years or so, the amount of C14 left is so small that it is practically unmeasurable.  It's for this reason that C14 dating is not much good for fossil dating, as most fossils are *much* older than 50,000 years.\n\n[Aside:  There's another reason carbon-14 dating is not useful for fossils.  It's only useful for dating once-living matter (bones, wood, teeth, shells, cloth, paper, etc.) that was incorporating carbon into its body while it lived ... either a plant that was once breathing CO2, or an animal that was eating things that contained carbon (like plants or other animals).  A fossil is not once-living matter.  It is rock that has filled in the impression left by a dead organism.  So fossils themselves may contain very little carbon of any type.]\n\nBut there are other atoms with a *much* longer half-life.  For example potassium-40 (K40) decays into argon-40 (Ar40) with a half-life of 1.26 *billion* years.  So when a rock is created by a volcano, it contains only K40 (as argon is a gas, so any Ar40 present at the time the rock forms escapes from the molten rock before it cools).  But over millions of years this K40 decays to Ar40, which remains trapped in the rock.  So a geologist can dig up a rock from a layer of strata, melt it down, and measure the amount of molten K40 and gaseous Ar40 that is released.  By the ratio of K40 to Ar40 in the rock, the geologist can calculate the age of the rock, in millions of years.  The geologist then also knows the age of anything else that was encased in the same layer of strata as the rock ... such as a fossil.\n\nCarbon-14 dating and potassium-argon dating are two forms of what are called 'radiometric dating'.  Other examples are uranium-lead dating (half-life of 700 million years), and rubidium-strontium dating (half-life of 50 billion years ... which is *very* long, considering that the earth is only 4.5 billion years old).
781038
I agree with birchardv here...........we need the rest of the problem, and you would learn a lot more if you did the homework yourself.  But do whatever floats your boat.  Add the rest of the problem and I'll get back to you.\n\nOkay Chemist, this problem is really long; if you want a good answer with plenty of steps, I'll need more room.  Email me and I'll send you the solution.
777912
Multiplu the time it takes to achieve half-life by the days required for a given amount of decay...\n\nSuch as 18.72 * .75\n\nI know you said not to give the answer, but you must understand that the question asks, how many days are required for 3/4 of the decay to decompose... \n\n The answer is by the days it takes for its half-life, multiplied by the desired ammount of decay.
938184
Firstly. it's not squared (even it says 2 on the top). It says how many electrons u got on that 1S sub shell and on 2P sub shell. Carbon has 6 electrons and these electrons filled in to sub shells according to Pauli's exclusion principle. 2 electrons filled into 1S sub shell, another 2 electrons to 2S sub shell and rest 2 electrons filled into 2P sub shell. Remember that (S) sub shells hold on 2 electrons and P sub shells can hold 6 electrons. But in this case after 4 electrons are filled into S sub shells and the balance is 2 electrons. So it can be filled into P. If there are electrons more than 6, for ex 10.. 2 goes into 1S, another 2 goes into 2S and rest 6 electrons fill into 2P. This is how it happens
266267
Since a humans are rather new to Earth (being as our ancestors have only been around for a million years +, we can use carbon dating. After death, carbon stops accumulating in our bodies. Carbon 14 decays at a rate of half every 5730 years. So if there is only 25% of Carbon left from the suspected original amount then 11460 years have gone by. If it is significantly old, other elements are used liuke Uranium etc...
152635
You program the data in to a calculator (like a TI-83), graph, and model the data points using an exponential profile.  It will then give you the form of the equation that best fits your data points in the form of a*e^(b*x), which you can then graph over your data points.  In your case, "b" should be negative to indicate decay.
677826
1) is already balanced... to be more precise\n2C2H6 + 7O2 --> 4 C02 + 6H2O\n\n2) Fe2O3 + (3)H2SO4 --> Fe2(SO4)3 + (3)H2O
815878
Radio-active decay is measured with half lives, that is a time when half the matter of a sample would have disintegrated.  That is a rate, which is not a speed, so the speed of light is totally unrelated.