Why do carbon compounds generally have low melting and boiling points?

Correct answer: The forces between their molecules are weak

Most carbon compounds are covalent and exist as separate molecules. The forces of attraction between these molecules are relatively weak, so less heat is needed to separate them; hence, their melting and boiling points are generally low. Substances with a strong ionic lattice usually have high melting points. Exam tip: The forces between covalent molecules are called intermolecular forces.