Organic compounds are built around carbon because a carbon atom
- A. forms four covalent bonds and can catenate into long chains and rings
- B. readily forms ions of charge four
- C. has a very large atomic radius
- D. always forms only single bonds
Explanation
With four valence electrons and a small radius, carbon forms four strong covalent bonds and bonds to itself almost as strongly as to other elements, so chains, branches and rings of unlimited length are possible. It also forms stable double and triple bonds, which silicon below it cannot do. Carbon rarely forms simple ions because removing or adding four electrons would cost far too much energy.