Characteristics of Covalent Compounds
1. Crystal Structure:
Crystal structure of covalent compounds is formed from atoms or molecules. Crystal of covalent compounds are divided in three parts as –
i. These are crystals of covalent compounds whose molecule are very small and these molecules are held together by vander waals forces.
Example: Sulphur, Iodine.
ii. These are crystals of covalent compounds whose molecule are very large due to combination of every atom with other atom by covalent bonds.
Example: Diamond, Silica.
iii. These are crystals of covalent compounds whose have separate layers.
2. Physical Nature:
Due to weaker force of attraction between the molecules of the covalent compounds, maximum covalent compounds are gases or liquids but some covalent compounds exist as solid like Urea, Sugar, Glucose, and Naphthalene.
Covalent compounds are not soluble in polar solvents like water but are soluble in non-polar solvent like alcohol, ether, carbon tetra chloride.
4. Melting Point and Boiling Point ( MP and BP) :
Melting and boiling points of covalent compounds are very low because very less energy is required to overcome the weak force of attraction between the neutral molecules in the covalent compound. But Diamond and Graphite are exception because they have very high melting and boiling points.
Covalent compounds do not have ions so they do not conduct electricity but some polar covalent compounds conduct very less electricity.