So the different versions of a given element, those are each called isotopes. I just view in my head as versions of an element.
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. They're cosmic particles. You can view them as just single protons, which is the same thing as a hydrogen nucleus. They can also be alpha particles, which is the same thing as a helium nucleus.
And there's even a few electrons. And they're going to come in, and they're going to bump into things in our atmosphere, and they're actually going to form neutrons. So they're actually going to form neutrons. And we'll show a neutron with a lowercase n, and a 1 for its mass number. And we don't write anything, because it has no protons down here. Like we had for nitrogen, we had seven protons.
So it's not really an element. It is a subatomic particle. But you have these neutrons form.
Carbon dating radioactive decay
And every now and then- and let's just be clear- this isn't like a typical reaction. But every now and then one of those neutrons will bump into one of the nitrogen'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.
So let me make it clear. So it bumps off one of the protons. So instead of seven protons we now have six protons. But this number 14 doesn't go down to 13 because it replaces it with itself. So this still stays at And now since it only has six protons, this is no longer nitrogen, by definition. This is now carbon. And that proton that was bumped off just kind of gets emitted.
So then let me just do that in another color. So plus. 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. Constant formation. 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.
Carbon dating, method of age determination that depends upon the decay to nitrogen of radiocarbon (carbon). Carbon is continually formed in nature by the interaction of neutrons with nitrogen in the Earth's atmosphere. Learn more about carbon dating in this article.
I won't go into the details of that. Main article: Suess effect. Archived from the original on Retrieved Bibcode : Sci Bibcode : Natur. Archived from the original on July 5, Archived from the original on 22 November Retrieved 22 November Martin Stute's homepage at Columbia.
Journal of Geophysical Research: Biogeosciences. Bibcode : JGRG. Earth and Planetary Science Letters. Journal of Geophysical Research: Atmospheres. Bibcode : JGRD. Archived from the original on Bronk Archived from the original on Nature Communications. Bibcode : NatCo Bibcode : PNAS.
Journal of Geophysical Research. Bibcode : JGR Nuclear Regulatory Commission. January 1, Progress in Nuclear Energy. Carbon Dioxide Information Analysis Center.
Carbon dating is a variety of radioactive dating which is applicable only to matter which was once living and presumed to be in equilibrium with the atmosphere, taking in carbon dioxide from the air for photosynthesis. Cosmic ray protons blast nuclei in the upper atmosphere, producing neutrons which in turn bombard nitrogen, the major constituent of the atmosphere. Let's Model Radioactive Decay to Show How Carbon Dating Works Charissa Van Straalen/Getty Images Radioactive material gets a bad rap, what with radiation and fallout and nuclear waste and all. Carbon Dating - The Premise Carbon dating is a dating technique predicated upon three things: The rate at which the unstable radioactive C isotope decays into the stable non-radioactive N isotope, The ratio of C to C found in a given specimen, And the ratio C to C found in the atmosphere at the time of the specimen's death.
University of Utrecht. August National Geographic News.
Gazit, Ehud ed. Bibcode : PLoSO Institute for Radiological Protection and Nuclear Safety. Archived from the original on 25 September Retrieved 9 Dec All other atmospheric carbon dioxide comes from young sources-namely land-use changes for example, cutting down a forest in order to create a farm and exchange with the ocean and terrestrial biosphere.
This makes 14C an ideal tracer of carbon dioxide coming from the combustion of fossil fuels. Scientists can use 14C measurements to determine the age of carbon dioxide collected in air samples, and from this can calculate what proportion of the carbon dioxide in the sample comes from fossil fuels.
How Does Carbon Dating Work
Bibcode : Metic. Physics Letters B. Bibcode : PhLB. National Council on Radiation Protection and Measurements.
Categories : Isotopes of carbon Environmental isotopes. Hidden categories: Webarchive template wayback links CS1: long volume value Isotope content page.
Decay energy MeV. Isotopes of carbon Complete table of nuclides. Carbon is an isotope of carbon.
Carbon Dating - Example of exponential decay