It is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds.
Three isotopes occur naturally, 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.
The physical properties of carbon vary widely with the allotropic form.
"coal") is a chemical element with symbol C and atomic number 6.
On the periodic table, it is the first (row 2) of six elements in column (group 14), which have in common the composition of their outer electron shell.