Carbon is the chemical element with symbol C and atomic number 6.
It is nonmetallic and tetravalent making four electrons available to form covalent chemical bonds. There are three naturally occurring isotopes, with Carbon-12 and Carbon-13 being stable, while Carbon-14 is radioactive, decaying with a half-life of about 5730 years. Carbon is one of the few elements known since antiquity. The name "carbon" comes from Latin language carbo, coal.
There are several allotropes of carbon of which the best known are graphite, Diamond, and amorphous carbon. The physical properties of carbon vary widely with the allotropic form. For example, Diamond is highly transparent, while graphite is opaque and black. Diamond is among the hardest materials known, while graphite is soft enough to form a streak on paper (hence its name, from the Greek word "to write"). Diamond has a very low electrical conductivity, while graphite is a very good conductor. Under normal conditions, diamond has the highest thermal conductivity of all known materials. All forms of carbon are highly stable, requiring high temperature to react even with oxygen. 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. Carbon is the fourth most abundant element in the universe by mass after hydrogen, helium and oxygen. It is present in all known lifeforms, and in the human body carbon is the second most abundant element by mass (about 18.5%) after oxygen. This abundance, together with the unique diversity of organic compounds and their unusual polymer-forming ability make this element the chemical basis of all known life.
Carbon has an affinity for bonding with other small atoms, including other carbon atoms, and is capable of forming multiple stable covalent bonds with such atoms. As a result, carbon is known to form almost ten million different compounds; the large majority of all chemical compounds.
Carbon also has the highest melting and sublimation point of all elements. Irrespective of its allotropic form, carbon remains solid at higher temperatures than the highest melting point of metals such as tungsten or rhenium. Although thermodynamically prone to oxidation, carbon resists oxidation more effectively than elements such as iron and copper.Most forms of carbon are comparatively unreactive under normal conditions. At standard temperature and pressure. It resists all but the strongest oxidizers. It does not react with sulfuric acid, hydrochloric acid, chlorine or any alkalis. At elevated temperatures carbon reacts with oxygen to form carbon oxides.
The base value of each unit of ranges between 1 and 15Ð per unit, with up to 3 units being found at any one time.
Presence on Mars: Common
|Group 1 | Group 2 | Group 3 | Group 4 | Group 5 | Group 6|
|Group 1|||Aluminum | Arsenic | Beryllium | Boron | Calcium | Cantite | Carbon | Chlorine | Chromium | Cobalt | Copper | Flourine | Helium| | Hydrogen | Iron | Lithium | Magnesium | Manganese | Nickel | Oxygen | Phosphorus | Plesium | Potassium | Silicon | Sodium||