Covalently bonded molecules have strong intramolecular bonds but weak intermolecular forces, resulting in low melting and boiling points. Since no charged particles are formed, these compounds are generally poor conductors of electricity.

Methane (CH₄) is formed by carbon sharing its four valence electrons with four hydrogen atoms, forming covalent bonds. The molecule lacks charged particles, contributing to its low melting and boiling points.

The electron dot structure of NH₃ shows that each hydrogen atom shares electrons with nitrogen, forming single covalent bonds and allowing all four atoms to attain stable noble gas configurations.

Carbon compounds have weak intermolecular forces, reflected in low melting and boiling points compared to ionic compounds. Their poor conductivity is attributed to the absence of ions in their bonding.

With four electrons in its outer shell, carbon aims to achieve noble gas configuration. However, gaining or losing four electrons is impractical due to the difficulty in holding or removing electrons, leading to the absence of ions in carbon compounds.