Chemical bonding: ionic, covalent and metallic, compared
Bonding questions ask you to predict properties from structure. Get the electron count right and the shape, polarity and boiling point follow.
What this covers
- Ionic, covalent and metallic bonding
- Lewis dot structures
- VSEPR shapes and bond angles
- Polarity and dipoles
- Intermolecular forces
Worked example
Problem
Predict the shape and bond angle of NH₃.
- 1Count electron domainsNitrogen has three bonding pairs and one lone pair — four domains.
- 2Base geometryFour domains give a tetrahedral arrangement.
- 3Account for the lone pairThe lone pair repels more strongly, compressing the angle from 109.5°.
Answer: Trigonal pyramidal, bond angle ≈ 107°
Mistakes that cost marks
- Counting only bonding pairs and ignoring lone pairs.
- Assuming polar bonds always give a polar molecule.
- Calling hydrogen bonding a covalent bond.
Questions students ask
How do I know if a molecule is polar?
Draw the shape, then add the bond dipoles as vectors — symmetric shapes cancel.
Practise structure and bonding until it sticks
Noeta remembers every step you missed and brings it back right before you forget it — 10 free questions a day, no card required.
Start free