GCSEA-LevelAQAEdexcelOCR

Bonding revision — GCSE & A-Level Chemistry

Q: Why does graphite conduct electricity but diamond does not?

In graphite each carbon forms three bonds, leaving one delocalised electron per atom that can move along the layers. In diamond every electron is in a localised bond, so none are free to carry charge.

Q: What is the difference between a polar bond and a polar molecule?

A polar bond has a permanent dipole due to a difference in electronegativity. A polar molecule has a net dipole — symmetrical molecules (like CO2) can have polar bonds but no overall dipole.

Q: Why are noble gases monatomic?

They have full outer shells, so they have no tendency to gain, lose or share electrons. They exist as single atoms with only weak London forces between them.

Q: Why are metals malleable?

The layers of positive ions can slide over each other without breaking the metallic bond, because the sea of delocalised electrons holds them together regardless of position.

Bonding explains why substances have the properties they do — melting points, conductivity, solubility, hardness. UK exam boards (AQA, Edexcel, OCR) consistently ask you to link bonding and structure to observed properties.

At A-Level the topic deepens into electronegativity, polarity, intermolecular forces (London, dipole-dipole, hydrogen bonding) and shapes of molecules using VSEPR. These ideas reappear in organic chemistry, acid-base chemistry and analytical chemistry.

At GCSE

At GCSE you draw dot-and-cross diagrams for ionic, covalent and metallic bonding and link structure (giant ionic, simple molecular, giant covalent, metallic) to properties such as melting point, conductivity and solubility.

At A-Level

At A-Level you add electronegativity, polarity and the three intermolecular forces (London, permanent dipole-dipole, hydrogen bonding). Expect VSEPR shape questions (bond angles, lone-pair repulsion) and explanations of anomalous boiling points such as water and HF.

Generate bonding flashcards now

The Recall tool is pre-loaded with high-quality bonding notes. Hit Generate to make a flashcard set instantly — or switch to quiz, summary or exam mode.

Bonding — key points:
- Ionic bonding: transfer of electrons from metal to non-metal forming oppositely charged ions held by strong electrostatic forces in a giant ionic lattice. High melting points; conduct when molten or dissolved.
- Covalent bonding: shared pair of electrons between non-metal atoms. Simple molecular substances (CO2, H2O) have low melting points (weak intermolecular forces). Giant covalent substances (diamond, graphite, SiO2) have very high melting points.
- Graphite conducts because delocalised electrons move along layers; diamond does not.
- Metallic bonding: lattice of positive ions in a sea of delocalised electrons. Good electrical/thermal conductors; malleable.
- A-Level: electronegativity is the ability of an atom to attract bonding electrons. A difference creates a polar bond. Three intermolecular forces in order of strength: London (induced dipole-dipole) < permanent dipole-dipole < hydrogen bonding.
- Shapes (VSEPR): linear 180°, trigonal planar 120°, tetrahedral 109.5°, trigonal pyramidal 107°, bent 104.5°. Lone pairs repel more than bonding pairs.

155 wordsTip: 100–500 words works best

Pick a subject chip above, paste your notes, choose a mode and hit Generate.

Example flashcards

Q: Why do ionic compounds conduct electricity when molten but not as solids?
A: When molten the ions are free to move and carry charge. In the solid lattice the ions are held in fixed positions.
Q: What type of bonding is present in diamond, and why is it so hard?
A: Giant covalent — each carbon is bonded to four others by strong covalent bonds in a rigid 3D lattice.
Q: Define electronegativity.
A: The ability of an atom to attract the pair of electrons in a covalent bond towards itself.
Q: Why does water have a higher boiling point than expected for its molecular mass?
A: Water molecules form hydrogen bonds between the lone pair on O and the H of another molecule — these are much stronger than the dipole-dipole or London forces of similar-sized molecules.

Quick summary

Bonding is a high-yield Chemistry topic for GCSE and A-Level students (AQA, Edexcel, OCR). At A-Level you add electronegativity, polarity and the three intermolecular forces (London, permanent dipole-dipole, hydrogen bonding). Examiners reward precise definitions and applied explanations — focus on the core ideas and the small set of terms that come up every series.

Key terms

Ionic bond
Covalent bond
Metallic bond
Electronegativity
Polar bond
Hydrogen bonding
London forces
Lattice
VSEPR

Bonding FAQs

Why does graphite conduct electricity but diamond does not?+

In graphite each carbon forms three bonds, leaving one delocalised electron per atom that can move along the layers. In diamond every electron is in a localised bond, so none are free to carry charge.

What is the difference between a polar bond and a polar molecule?+

A polar bond has a permanent dipole due to a difference in electronegativity. A polar molecule has a net dipole — symmetrical molecules (like CO2) can have polar bonds but no overall dipole.

Why are noble gases monatomic?+

They have full outer shells, so they have no tendency to gain, lose or share electrons. They exist as single atoms with only weak London forces between them.

Why are metals malleable?+

The layers of positive ions can slide over each other without breaking the metallic bond, because the sea of delocalised electrons holds them together regardless of position.

Save your bonding flashcards

Create a free account to save study sets, track progress and revise on any device.

Create free account Browse all subjects