Chapter summary

Bonding and Structure, at a glance

Revisit the key comparisons, then return to any explanation you need.

O-Level 2026 SEC G3 2027

Bring it together

Quick revision

For every explanation: name the particles, identify the attraction, and say what can move.

Structure at a glance
Structure and particles	Melting	Electrical conductivity
IonicNaClPositive and negative ions	High: strong electrostatic attractions throughout the lattice.	Solid: no. Molten or dissolved: yes, mobile ions.
Simple molecularMethane, iodineSeparate molecules	Generally low: weak intermolecular forces are overcome, not covalent bonds.	Pure solid or liquid: generally no mobile charged particles.

Metals: generally solid, with high melting and boiling points; conduct heat and electricity and are malleable. Alloys: mixtures containing a metal and other elements; identify more than one type of atom in the diagram.

Three useful corrections

Not conducting? Check whether charged particles can move, not just whether they exist.

Low melting point? Name the weak intermolecular forces, not "weak covalent bonds".

NaCl formula? It gives an ion ratio in a lattice, not a separate molecule.

Revisit an explanation

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