Carbon 14 dating half life
It's just a little section of the surface of the Earth. And that carbon-14 that you did have at you're death is going to decay via beta decay-- and we learned about this-- back into nitrogen-14. So it'll decay back into nitrogen-14, and in beta decay you emit an electron and an electron anti-neutrino. But essentially what you have happening here is you have one of the neutrons is turning into a proton and emitting this stuff in the process. So I just said while you're living you have kind of straight-up carbon-14. What it's essentially saying is any given carbon-14 atom has a 50% chance of decaying into nitrogen-14 in 5,730 years. And it has seven protons, and it also has seven neutrons. So the different versions of a given element, those are each called isotopes. So anyway, we have our atmosphere, and then coming from our sun, we have what's commonly called cosmic rays, but they're actually not rays. You can view them as just single protons, which is the same thing as a hydrogen nucleus. But every now and then one of those neutrons will bump into one of the nitrogen-14's in just the right way so that it bumps off one of the protons in the nitrogen and essentially replaces that proton with itself. But this number 14 doesn't go down to 13 because it replaces it with itself. And now since it only has six protons, this is no longer nitrogen, by definition. And that proton that was bumped off just kind of gets emitted. But this process-- and once again, it's not a typical process, but it happens every now and then-- this is how carbon-14 forms. You can essentially view it as a nitrogen-14 where one of the protons is replaced with a neutron. It makes its way into oceans-- it's already in the air, but it completely mixes through the whole atmosphere-- and the air. And plants are really just made out of that fixed carbon, that carbon that was taken in gaseous form and put into, I guess you could say, into kind of a solid form, put it into a living form. It gets put into plants, and then it gets put into the things that eat the plants. Well, the interesting thing is the only time you can take in this carbon-14 is while you're alive, while you're eating new things. Carbon dating has given archeologists a more accurate method by which they can determine the age of ancient artifacts. Libby invented carbon dating for which he received the Nobel Prize in chemistry in 1960.So the rate at which this happens, so the rate of carbon-14 decay, is essentially half disappears, half gone, in roughly 5,730 years. Even better, maybe you dig a little deeper, and you find another bone. And you say, wow, you know this thing right over here has 1/4 the carbon-14 that I would expect to find in something living. Well, if it only has 1/4 the carbon-14 it must have gone through two half lives.After one half life, it would have had 1/2 the carbon.When these energetic neutrons collide with a nitrogen-14 (seven protons, seven neutrons) atom it turns into a carbon-14 atom (six protons, eight neutrons) and a hydrogen atom (one proton, zero neutrons).Since Nitrogen gas makes up about 78 percent of the Earth's air, by volume, a considerable amount of Carbon-14 is produced.
And so this would involve two half lives, which is the same thing as 2 times 5,730 years. You'd say this thing is 11,460 years old, give or take.
The carbon-14 atoms combine with oxygen to form carbon dioxide, which plants absorb naturally and incorporate into plant fibers by photosynthesis.
Animals and people take in carbon-14 by eating the plants.
To measure the amount of radiocarbon left in a artifact, scientists burn a small piece to convert it into carbon dioxide gas.
Radiation counters are used to detect the electrons given off by decaying Carbon-14 as it turns into nitrogen.