The extra neutrons in Carbon's case make it radioactive (thus the term, but dating these samples require a correction for the “reservoir effect” a process. Radiocarbon dating is a method for determining the age of an object containing organic . N in the upper atmosphere would create C. It had previously been . Carbon dating is something that you hear about in the news all the time. Find out how carbon dating works and why carbon dating is so accurate!.
Carbon 14 dating 2 :
And this is actually called a half life. But this process-- and once again, it's not a typical process, but it happens every now and then-- this is how carbon forms.
How Carbon-14 Dating Works
Carbon dating process video of making - Radiometric dating
And that proton that was bumped off just kind of gets emitted. So then let me just do that in another color. And a proton that's just flying around, you could call that hydrogen 1. And it can gain an electron some ways. If it doesn't gain an electron, it's just a hydrogen ion, a positive ion, either way, or a hydrogen nucleus. But this process-- and once again, it's not a typical process, but it happens every now and then-- this is how carbon forms.
So this right here is carbon You can essentially view it as a nitrogen where one of the protons is replaced with a neutron. And what's interesting about this is this is constantly being formed in our atmosphere, not in huge quantities, but in reasonable quantities. So let me write this down. And let me be very clear.
Let's look at the periodic table over here. So carbon by definition has six protons, but the typical isotope, the most common isotope of carbon is carbon So carbon is the most common.
So most of the carbon in your body is carbon But what's interesting is that a small fraction of carbon forms, and then this carbon can then also combine with oxygen to form carbon dioxide. And then that carbon dioxide gets absorbed into the rest of the atmosphere, into our oceans. It can be fixed by plants. When people talk about carbon fixation, they're really talking about using mainly light energy from the sun to take gaseous carbon and turn it into actual kind of organic tissue.
And so this carbon, it's constantly being formed. It makes its way into oceans-- it's already in the air, but it completely mixes through the whole atmosphere-- and the air. And then it makes its way into plants. 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.
That's what wood pretty much is. It gets put into plants, and then it gets put into the things that eat the plants. So that could be us. Now why is this even interesting? I've just explained a mechanism where some of our body, even though carbon is the most common isotope, some of our body, while we're living, gets made up of this carbon thing. Well, the interesting thing is the only time you can take in this carbon is while you're alive, while you're eating new things.
Because as soon as you die and you get buried under the ground, there's no way for the carbon to become part of your tissue anymore because you're not eating anything with new carbon And what's interesting here is once you die, you're not going to get any new carbon And that carbon that you did have at you're death is going to decay via beta decay-- and we learned about this-- back into nitrogen So kind of this process reverses.
So it'll decay back into nitrogen, and in beta decay you emit an electron and an electron anti-neutrino. I won't go into the details of that. 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. Now why is this interesting? So I just said while you're living you have kind of straight-up carbon And carbon is constantly doing this decay thing.
But what's interesting is as soon as you die and you're not ingesting anymore plants, or breathing from the atmosphere if you are a plant, or fixing from the atmosphere. And this even applies to plants. Once a plant dies, it's no longer taking in carbon dioxide from the atmosphere and turning it into new tissue. The carbon in that tissue gets frozen. And this carbon does this decay at a specific rate.
And then you can use that rate to actually determine how long ago that thing must've died. So the rate at which this happens, so the rate of carbon decay, is essentially half disappears, half gone, in roughly 5, years. And this is actually called a half life. And we talk about in other videos. This is called a half life. And I want to be clear here. You don't know which half of it's gone. It's a probabilistic thing. And so you can look back to that layer of bark just for the half life of carbon, and then figure out how much carbon was there in the atmosphere at that period in time.
And so it's kind of a record of the atmosphere up to 10, years. If you want to go even further back, you can look at cave deposits, and the fancy word for these cave deposits are speleothems. You might be familiar with stalagmites. Those are those speleothems that are kind of coming out of the bottom of the cave, or stalactites. Those are the speleothems that are coming from the top of the cave. But the reason why these are useful is these are formed by calcium carbonate, so they have carbon in them, and slowly over, really, tens of thousands of years, the water in the cave deposits that calcium carbonate.
So it's a record of the fraction of carbon in some of those years. And you can go down to resolutions of as small as 10 years. And so this will give us pretty good estimates over tens of thousands of years, up to 50, years. And frankly, carbon isn't even useful beyond, really, 50, or 60, years.
So this gives us a good record of carbon in the atmosphere, assuming that it's fairly uniform throughout the atmosphere, and all evidence suggests that, and that that uniformity through the atmosphere also goes into the water supply, and into living plants and animals.
Now, the other thing, and I looked into this a little bit, it actually turns out because we are spewing so much fossil fuel right now, we are changing the amount, or the proportion of carbon much, much faster than has happened in other time periods.