Properties of simple molecular substances

https://www.youtube.com/watch?v=0ezyQMc4iqw

Whats simple molecular substance

In these substances, the atoms are covalently bonded to each other

They have small molecules with fixed number of atoms. e.g every molecule of water has one atom of oxygen and two atoms of hydrogen

They have low melting and bp due to weak intermolecular forces

What does solubility of simple molecular substance depend on

Whether the substance is polar or non polar

What is general rule on solubility of non polar substances

They dissolve very well in non polar solvents

When non polar substance like iodine dissolves in non polar solvent , the solvent molecules form london forces to the iodine molecules.

Non polar substances are insoluble in polar solvents (e.g water)

If we add iodine to water, the water molecules remain hydrogen bonded to each other, rather than forming london forces with iodine molecules

What is general rule on solubility of simple molecular substances that are polar

Polar substances dissolve in polar solvents.

However polar substances are usually insoluble in non polar solvents

Why can simple molecular substances not conduct electricitry

They do not contain mobile charged particles,