What are 3 characteristics of carbon that make it a unique element

1)Carbon is abundant and common
2)forms strong covalent bonds
3)has four valence electrons
4)variety of shapes
5)bonds with multiple elements.

(1) Although it is a nonmetal, the graphite allotropic form of carbon conducts electricity, because only three out of four of its valence electrons are shared with other surrounding carbon atoms, allowing the fourth one to wander from atom to atom reminiscent of a metallic bond.
(2) Carbon has the ability to form covalent bonds with other carbon atoms forming continuous chains, branches, and loops. Consequently, theoretically there is no limit to compounds of carbon that are the subject of organic chemistry.
(3) Carbon compounds are the backbone of all organic compounds that are the basic building blocks of all living things.