Carbon atom

Carbon Atom

The carbon atom is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table.

Characteristics

Carbon atoms are unique in their ability to form stable, extended, covalent compounds, including complex geometries and various molecular architectures with different bonding scenarios. Carbon forms more compounds than any other element, with almost ten million pure organic compounds described to date, which in turn are a tiny fraction of such compounds that are theoretically possible under standard conditions.

Isotopes

Carbon has several isotopes, of which three are naturally occurring. The most abundant is Carbon-12, which makes up 99% of all carbon on Earth. Carbon-13 is also stable, representing about 1.1% of all carbon. The remaining 0.01% is Carbon-14, a radioactive isotope with a half-life of 5730 years.

Role in Life

Carbon is the fourth most abundant element in the universe by mass after hydrogen, helium, and oxygen. Carbon's abundance, its unique diversity of organic compounds, and its unusual ability to form polymers at the temperatures commonly encountered on Earth enables this element to serve as a common element of all known life. It is the second most abundant element in the human body by mass (about 18.5%) after oxygen.

Allotropes

The allotropes of carbon include graphite, one of the softest known substances, and diamond, the hardest naturally occurring substance. It also includes fullerene, carbon nanotubes, carbon black, and many other forms.

See Also

• Chemical element
• Periodic table
• Chemical bond
• Isotope
• Organic compound