Give reasons — Hydrogen chloride can be termed as a polar covalent compound.

Give a reason why covalent compounds exist as gases, liquids or soft solids?

There are three elements E, F, G with atomic numbers 19, 8 and 17 respectively. Give the molecular formula of the compound formed between E and G and state the type of chemical bond in this compound.

Define a coordinate bond and give the conditions for its formation.