carbon 12 I think
Carbon-14 because it has 2 more neutrons.
32g
There are more carbon atoms in 48 grams of CO2 than in 12 grams of diamond
Carbon-12 is the most abundant of the two stable isotopes of the element carbon, accounting for 98.89% of carbon; it contains 6 protons, 6 neutrons, and 6 electrons. Carbon-12 is a single Carbon atom. In chemistry, a molecule is defined as a sufficiently stable, electrically neutral group of at least two atoms in a definite arrangement held together by very strong chemical bonds.
carbon 14 is a isotop of carbon 12.
Carbon
The 12 in Carbon-12 designates the isotope which has an atomic mass of 12. This is the most abundant isotope of carbon. Carbon has an atomic number of 6, therefore it has 6 protons. Carbon 12, therefore has 6 neutrons. Carbon 14 is another isotope of carbon, still having 6 protons, but has 8 neutrons, so it has an atomic mass of (6 + 8 = 14). See related link for more information on carbon isotopes.
Every sixth number for 12 and more will be an abundant number
Carbon-12 and carbon-13 are stable. The fact that carbon-14 is unstable, with a relatively short half-life (very short compared to the age of the Solar System) means that it must needs have been produced more recently than the creation of the Solar System.
As much as two-thirds of Earth's carbon may be hidden in the inner core, making it the planet's largest carbon reservoir.Read more at: http://phys.org/news/2014-12-earth-carbon-hidden-planet-core.html
If you mean which isotope, then carbon-12 is the most abundant. If you mean where does the carbon come from, then it's atmospheric carbon dioxide for plants, and food for animals.
Carbon 12 has 6 protons and 6 neutrons. Carbon 14 has 6 protons and 8 neutrons. Carbon 12 is abundant in the environment, accounting for 98.89% of all carbon and is a stable isotope of carbon. Carbon 14 accounts for only about 1 trillionth of all of the carbon on Earth and is radioactive, with a half life of roughly 5700 years, which makes it good for use in dating fossils etc
Carbon - 14 has two more electrons than carbon - 12.
Carbon 14 is different from other forms of carbon in 2 ways. It has more neutrons than any other isotope of carbon and is radioactive, emitting beta particles to decay into nitrogen-14.
As the atomic number of nitrogen is 7, the most abundant isotope of this atmospheric gas must have 7 neutrons (14.007 - 7 = about 7), and this will make nitrogen-14 that isotope that is most abundant.
Carbon-14 because it has 2 more neutrons.
it is abundant