Explain briefly why the student has grouped the different bonds like this?
Intra-molecular bonds are bonds that happen within a molecule.
- Covalent is obvious, atoms are sharing electrons.
- With ionic, the electrons are being donated and are attracted by ionic charges.
- With metallic, the anions are held together by the delocalised electrons.
Inter-molecular "bonds" happen between molecules.
Hydrogen bonds occur when hydrogen is polarized to become electropositive in a molecule due to the higher electronegativity from another atom, and then interacts with a very electronegative end of a polar molecule.
van De Waals forces occur from permanent dipoles in a molecule creating positive and negative regions.