Its density fluctuates from 2.25 g/cm³ (1.30 ounces/in³) for graphite and 3.51 g/cm³ (2.03 ounces/in³) for diamond.
The melting point of graphite is 3500ºC (6332ºF) and the extrapolated boiling point is 4830ºC (8726ºF).
Chemically pure carbon can be prepared by termic decomposition of sugar (sucrose) in absence of air.
In diamond, each carbon atom bonds to four others in a dense network that makes the material the hardest substance known.
[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.
Just the facts Carbon: From stars to life 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.
In older stars that have burned most of their hydrogen, leftover helium accumulates.
Each helium nucleus has two protons and two neutrons.