Carbon’s ability to form large and complex molecules has contributed to the great diversity of life.
1) A carbon atom has four electrons in its outer most energy level. To be stable a carbon atom needs eight electrons in its outermost level, a carbon atom therefore readily forms four covalent bonds with other elements.
2) Carbon also readily bonds with other carbon atoms, forming straight chains, branched chains or rings.
3) This tendency of carbon to bond with itself results in an enormous variety of organic compounds.