Thus carbon-14 has six protons and eight neutrons.) Carbon-12 is by far the most abundant carbon isotope, and carbon-12 and -13 are both stable.
But carbon-14 is slightly radioactive: it will spontaneously decay into nitrogen-14 by emitting an anti-neutrino and an electron, with a half-life of 5730 years.
Carbon has an atomic number of 6, an atomic weight of 12.011, and has three isotopes: carbon-12, carbon-13, and carbon-14.
(The numbers 12, 13 and 14 refer to the total number of protons plus neutrons in the atom's nucleus.
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View the full list Radiocarbon dating has transformed our understanding of the past 50,000 years.
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The technique is based on measuring the ratio of two isotopes of carbon.
Rarely do we have people from thousands of years ago who are writing, who are signing confessions.
So there's no one easy way that we know what the date of the pyramids happens to be. The pyramids are surrounded by cemeteries of other tombs. Sometimes we find organic materials, like fragments of reed, and wood, wooden coffins.
The theory behind radiocarbon dating is as follows: Why doesn't the carbon-14 in the air decay along with terrestrial carbon? The trick is that radioactive carbon-14 is continually replenished in a complex reaction that involves high-energy cosmic rays striking the upper atmosphere.
In this process, nitrogen-14 (7 protons and 7 neutrons) gains a neutron and loses a proton, producing carbon-14 (6 protons and 8 neutrons).
We study the pottery and how it changes over the broad sweep, some 3,000 years.