All carbon allotropes are solids under normal conditions, with graphite being the most thermodynamically stable form.They are chemically resistant and require high temperature to react even with oxygen.
The system of carbon allotropes spans a range of extremes: Atomic carbon is a very short-lived species and, therefore, carbon is stabilized in various multi-atomic structures with different molecular configurations called allotropes.The three relatively well-known allotropes of carbon are amorphous carbon, graphite, and diamond.It belongs to group 14 of periodic table Carbon is the 15th most abundant element in the Earth's crust, and 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.
The physical properties of carbon vary widely with the allotropic form.
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.
For example, graphite can be oxidised by hot concentrated nitric acid at standard conditions to mellitic acid, C Carbon sublimes in a carbon arc which has a temperature of about 5,800 K (5,530 °C; 9,980 °F).
Thus, irrespective of its allotropic form, carbon remains solid at higher temperatures than the highest melting point metals such as tungsten or rhenium.
For example, graphite is opaque and black while diamond is highly transparent.