How to carbon dating
Atoms are arranged as a nucleus surrounded by an electron cloud, with electrons zinging around at different distances from the nucleus.Chemists conceive of these distances as shells, and define the properties of atoms by what is in each shell, according to the University of California, Davis.[See Periodic Table of the Elements] Carbon occurs naturally as carbon-12, which makes up almost 99 percent of the carbon in the universe; carbon-13, which makes up about 1 percent; and carbon-14, which makes up a minuscule amount of overall carbon but is very important in dating organic objects.As the sixth-most abundant element in the universe, carbon forms in the belly of stars in a reaction called the triple-alpha process, according to the Swinburne Center for Astrophysics and Supercomputing.Under very hot temperatures — greater than 100,000,000 Kelvin (179,999,540.6 F) — the helium nuclei begin to fuse, first as pairs into unstable 4-proton beryllium nuclei, and eventually, as enough beryllium nuclei blink into existence, into a beryllium plus a helium.The end result: Atoms with six protons and six neutrons — carbon.Plants take it up in respiration, in which they convert sugars made during photosynthesis back into energy that they use to grow and maintain other processes, according to Colorado State University.
Because organisms stop taking in carbon-14 after death, scientists can use carbon-14's half-life as a sort of clock to measure how long it has been since the organism died.
Carbon has four empty spaces in its outer shell, enabling it to bond to four other atoms.
(It can also bond stably to fewer atoms by forming double and triple bonds.) In other words, carbon has options.
And it uses them: Nearly 10 million carbon compounds have been discovered, and scientists estimate that carbon is the keystone for 95 percent of known compounds, according to the website Chemistry Explained.
Carbon's incredible ability to bond with many other elements is a major reason that it is crucial to almost all life. The element was known to prehistoric humans in the form of charcoal.