Lesson 4.5 - Simple Covalent Properties

States of matter

Simple covalent molecules are usually liquids or gases.

They are rarely solids, due to their low melting point.

Melting and boiling point

Simple covalent molecules typically have low melting and boiling points.

This is because the intermolecular forces (between molecules) are weak.

The molecules can therefore be seperated easily.

Note: When melting or boiling, the intermolecular forces are broken. The bonds inside each molecule are not broken.

Size of molecules

The strength of intermolecular forces increases with the size of the molecule.

This means that larger molecules have stronger forces, and therefore also a higher melting and boiling point.

Conductivity

Simple covalent compounds do not conduct electricity.

This is because there are no delocalised electrons, and the molecules have no overall charge.