Question

Elements forming ionic compounds attain noble gas electronic configuration by either gaining or losing electrons from their valence shells. Explain giving reason why carbon cannot attain such a configuration in this manner to form its compounds. Name the type of bonds formed in ionic compounds and in the compounds formed by carbon. Also explain the reason why carbon compounds are generally poor conductors of electricity.

Answer 1

The atomic number of carbon is 6. This means that it has 4 electrons in its outermost shell and it needs 4 more electrons to attain noble gas electronic configuration. It cannot form C⁴⁺ cation, as the removal of 4 valence electrons requires a huge amount of energy. Moreover, the cation formed will have 6 protons and 2 electrons which makes carbon highly unstable. Carbon cannot form C⁴⁻ anion, as its nucleus with 6 protons cannot hold 10 electrons. Thus, carbon achieves noble gas electronic configuration by sharing its 4 electrons with other elements; it forms covalent compounds.
In ionic compounds, ionic bonds are formed, while in carbon compounds, covalent bonds are formed.
As carbon compounds are covalent in nature and lack free electrons so they are bad conductors of electricity.