BETAThis platform is under active development; bugs, missing features, and risk of data loss are present. Thank you for your support!

Giant Structures

Learn it by playing

Answer these questions to earn energy, then fish and explore. No account needed.

For teachers: ready-to-use lesson slides, revision notes for Giant Structures (Chemistry, CIE) — use them in your lesson, or run the topic as an interactive class activity your students play as a live game.

Lesson notes

Introduction to Giant Structures

  • Giant covalent structures contain billions of non-metal atoms joined by strong covalent bonds in a giant lattice.
  • Diamond and graphite are allotropes of carbon – same element, different bonding arrangements.
  • Giant structures have very high melting points due to many strong bonds.
  • Silicon(IV) oxide (SiO₂) is also a giant covalent compound.

Diamond – Structure & Properties

  • Each carbon atom bonds to four others in a tetrahedral arrangement.
  • All bonds are identical, very strong covalent bonds; no intermolecular forces.
  • Does not conduct electricity – all outer electrons are used in bonds.
  • Extremely hard and dense – used in cutting tools and drills.
  • Very high melting point – many strong bonds need lots of energy to break.
  • Hard but brittle (can be smashed with a hammer).

Diamond — giant covalent structure

Diamond — giant covalent structureCCCCCCCCCCCCCCCarbon atomStrong covalentbondEach carbonbonds to 4others

Graphite – Structure & Properties

  • Each carbon atom bonds to three others, forming layers of hexagons.
  • One delocalised electron per carbon atom is free to move between layers.
  • Conducts electricity – delocalised electrons carry charge.
  • High melting point – strong covalent bonds within layers.
  • Slippery – layers held by weak intermolecular forces can slide over each other.
  • Used as a lubricant, in pencils, and as electrodes (unreactive, conducts).

Graphite — giant covalent structure (layers)

Graphite — giant covalent structure (layers)e⁻e⁻e⁻e⁻e⁻e⁻DelocalisedelectronLayer of carbonatomsWeak forcesbetween layers

Silicon(IV) Oxide (SiO₂)

  • Giant covalent structure – each Si bonds to 4 O atoms, each O bonds to 2 Si atoms.
  • Forms a tetrahedral arrangement similar to diamond.
  • Very hard, high melting point, insoluble in water, does not conduct electricity.
  • Occurs naturally as sand and quartz.
  • Used to make sandpaper and to line furnaces (cheap, heat-resistant).

Silicon(IV) oxide (SiO₂) — giant covalent structure

Silicon(IV) oxide (SiO₂) — giant covalent structureOOOOOOOOSiSiSiSiSiSiSiSiSilicon atomOxygen atomEach Si bonds to4 O atoms

Metallic Bonding

  • Metals consist of a giant lattice of positive metal ions surrounded by a ‘sea of delocalised electrons’.
  • The metallic bond is the electrostatic attraction between positive ions and delocalised electrons.
  • High melting/boiling points – strong metallic bonds require lots of energy to break.
  • Good conductors of heat and electricity – delocalised electrons move freely.
  • Malleable and ductile – layers of ions can slide over each other without breaking bonds.

Metallic bonding

Magnesium — metallic bondinge⁻e⁻e⁻e⁻e⁻e⁻e⁻e⁻e⁻Mg²⁺Mg²⁺Mg²⁺Mg²⁺Mg²⁺Mg²⁺Mg²⁺Mg²⁺Mg²⁺Mg²⁺Mg²⁺Mg²⁺Mg²⁺Mg²⁺Mg²⁺Mg²⁺Positive metalionSea ofdelocalisedelectrons

Slides

Sign up free to view the lesson slides

Step through every slide for this topic — plus flashcards and revision notes — with a free account.

Practice questions

Free preview — 8 of 53 questions. Sign up to see them all.
  1. 1.Which statement about carbon allotropes is correct?

    Medium
    • ADiamond contains carbon atoms bonded to three other carbon atoms.
    • BGraphite is a good conductor of electricity because of the presence of mobile ions.
    • CDiamond is used as a lubricant because of the weak intermolecular forces between its layers.
    • DGraphite is a good conductor of electricity because it contains delocalised electrons.
  2. 2.Which row describes how graphite can be used in electrolysis?

    Medium
    • ADelocalised electrons – conducts electricity
    • BDelocalised electrons – acts as an insulator
    • CLow melting point – acts as an insulator
    • DLow melting point – conducts electricity
  3. 3.Which statement correctly describes the bonding in metals?

    Easy
    • AA lattice of negative ions in a 'sea of electrons'.
    • BA lattice of positive ions in a 'sea of electrons'.
    • CA lattice of neutral atoms with delocalised electrons.
    • DA lattice of negative ions with delocalised electrons.
  4. 4.Which row provides a correct description of the properties of metals?

    Easy
    • Amelting point high, boiling point low, conducts electricity yes
    • Bmelting point low, boiling point high, conducts electricity yes
    • Cmelting point low, boiling point low, conducts electricity no
    • Dmelting point high, boiling point high, conducts electricity yes
  5. 5.What other property does graphite have that makes it useful for electrodes?

    Medium
    • AGraphite is an unreactive substance and doesn’t react with the electrolyte.
    • BGraphite is soft and easy to shape into electrodes.
    • CGraphite has a low melting point due to the weak forces in between the layers.
    • DGraphite dissolves readily in water.
  6. 6.Which of the following statements about graphite and diamond are incorrect? 1 They are allotropes of carbon. 2 They both conduct electricity. 3 They form different numbers of bonds within their structures. 4 They have different uses.

    Medium
    • A2 and 3
    • B2 only
    • C1, 3 and 4
    • D2 and 4
  7. 7.Which statement correctly describes the structure of macromolecules?

    Medium
    • AGiant molecular crystal which is held together by weak intermolecular forces.
    • BGiant molecular crystal which is held together by strong ionic bonds.
    • CGiant molecular crystal which is held together by weak metallic bonds.
    • DGiant molecular crystal which is held together by strong covalent bonds.
  8. 8.Which statement about graphite and diamond is not correct?

    Medium
    • AGraphite is a good lubricant due to the weak forces in between the layers.
    • BDiamond is used as a drill tip because it is an extremely hard substance.
    • CGraphite has a low melting point due to the weak forces in between the layers.
    • DDiamond is an allotrope of carbon.

Unlock all 53 questions & more

Create a free account to see every question, the slides, flashcards and revision notes for this topic.

Past papers

Past-paper practice for this topic is coming soon.
Coming soon