Revision Notes MCQ Bank SAQ Bank Study Cards Courses Teachers Blog
Edexcel A Level Chemistry

Shapes of Molecules

Molecular shape depends on the number of bonding pairs and lone pairs around a central atom. These pages separate the key geometries so that students can revise electron-pair repulsion, bond angles and how lone pairs change the final shape.

Exam Papers
Paper 1 & 2
9CH0/01 and 9CH0/02
Specification Points
2.10 – 2.12
3 points covered
Sub-topics
11 lessons
Revision notes available
Exam Board
Edexcel
Pearson 9CH0

Revision Notes

11 revision notes, in the order the specification teaches them.

A linear molecule with two atoms in a straight line
1

Linear

Revise linear molecules with two bonding regions around the central atom and a bond angle of 180°.

Start revising
A trigonal planar molecule with three atoms around a centre
2

Trigonal Planar

Learn trigonal planar geometry, where three bonding regions arrange at 120° around the central atom.

Start revising
A tetrahedral molecule with four atoms around a centre
3

Tetrahedral

Revise tetrahedral molecules with four bonding pairs and bond angles of about 109.5°.

Start revising
A pyramidal molecule with three atoms and one lone pair
4

Trigonal Pyramidal

Understand how one lone pair changes a tetrahedral electron-pair arrangement into a trigonal pyramidal shape.

Start revising
A bent molecule with two atoms and two lone pairs
5

Bent

Learn how lone pairs compress bond angles and produce bent or V-shaped molecules such as H₂O.

Start revising
A trigonal bipyramidal molecule with five atoms
6

Trigonal Bipyramidal

Revise five-region electron-pair geometry with axial and equatorial positions.

Start revising
An octahedral molecule with six atoms
7

Octahedral

Learn octahedral geometry, where six bonding regions arrange at 90° around the central atom.

Start revising
A square planar molecule with two lone pairs
8

Square Planar

Revise square planar shapes formed from octahedral electron-pair arrangements with two opposite lone pairs.

Start revising
A square pyramidal molecule with one lone pair
9

Square Pyramidal

Understand square pyramidal molecules and how one lone pair affects an octahedral arrangement.

Start revising
A T-shaped molecule with two lone pairs
10

Distorted T

Learn distorted T-shaped molecules where lone pairs alter the arrangement of bonding pairs around the central atom.

Start revising
A seesaw molecule with one lone pair
11

SeeSaw

Revise seesaw shapes formed from trigonal bipyramidal electron-pair arrangements with one lone pair.

Start revising

Summary Map

Download, print and revise the key facts of this topic at a glance.

Summary map

Download, print and revise the key facts of this topic at a glance.

Illustration of a summary map: compounds joined by reaction arrows
Summary map · PDF

Shapes of Molecules Map

Edexcel A Level Chemistry · Topic 2 Bonding and Structure · Shapes of Molecules

The whole section on one A4 page: electron-pair repulsion, every shape from two to six pairs, lone pairs, related species and polar molecules.

Download the map6 key ideas + a table of shapes · A4 portrait · print ready

© 2026 Online Learning System. For personal study: printing is allowed; editing, copying and redistribution are not.

Virtual Lessons

Recorded video lessons that teach the topic step by step.

Illustration of a video lesson playing on a screenWith the course

Virtual Lessons

Taught step by step in 2 recorded video lessons, to watch at your own pace.

Topic 2A Shapes of Molecules taught by a specialist chemistry teacher, in 2 recorded video lessons that follow the specification.

  • Learn it before you revise itEach lesson explains the chemistry step by step, with the diagrams, mechanisms and worked examples the exam expects.
  • At your own pacePause, rewind and rewatch any part. Each lesson opens where you stopped.
  • Your progress is keptA lesson is ticked off once you have watched most of it, here and in your course on Moodle.

MCQ Bank

Multiple-choice papers on this topic, marked the moment you submit. MCQ (A) is free.

Illustration of a multiple-choice paper with one answer tickedMCQ (A) free

Test yourself: 2 MCQ papers

Exam-style multiple-choice papers, marked the moment you submit with every answer explained. MCQ (A) is free.

2 exam-style multiple-choice papers, MCQ (A) to (B): 42 questions on Topic 2A Shapes of Molecules, written the way the exam asks them.

  • Marked the moment you submitYour score straight away, with every answer explained, right or wrong.
  • Revise what you missedEach explanation links to the revision notes for that point.
  • MCQ (A) is freeTry the first paper now. MCQ (B) comes with the course.
Get the full course · £10.20
Open this topic in the MCQ Bank

SAQ Bank

Written, drawn and worked exam practice on this topic, marked by a specialist chemistry teacher.

Illustration of a written exam paper with a drawn structure and a penWith the course

Written and drawn answers: 3 papers

Draw, write and calculate the way the exam asks, then a specialist chemistry teacher marks your work.

3 exam papers, (A) to (C): 34 questions on Topic 2A Shapes of Molecules with no multiple choice. You write explanations, work out calculations and draw answers: structures, mechanisms and diagrams.

  • Answer the way the exam asksThe real paper wants written, worked and drawn answers, so that is how you practise.
  • Marked by a teacher, assisted by KASPA specialist chemistry teacher marks every answer against the mark scheme, with feedback on what to fix.
  • One paper marked each weekYour marked paper comes back here with every marking point shown.
Get the full course · £10.20
Open this topic in the SAQ Bank

Revision Game

Match reagents to products, with your board's reagents and conditions.

Coming soon

The revision game for Shapes of Molecules is being built.

Study Cards

Pick a deck, then turn each card to check what you remember.

Specification

Every specification point in this topic, in the exam board's own words. Rate how confident you are with each one.

Official Pearson Edexcel documentsSpecification (opens the Pearson Edexcel website in a new tab)Data booklet (opens the Pearson Edexcel website in a new tab)

Self-assessment · 56 points

Sign in to rate how confident you feel about each point. Your ratings are saved to your account, follow you to any device, and appear beside your KASP analytics, kept apart from your marks.

Sign in to rate yourself
0 Confident0 Getting there0 Not yet56 Not rated

2

  1. A.1

    know that ionic bonding is the strong electrostatic attraction between oppositely charged ions

    Revise
  2. A.2 a

    understand the effect of ionic radius on the strength of ionic bonding

    Revise
  3. A.2 b

    understand the effect of ionic charge on the strength of ionic bonding

    Revise
  4. A.3 a

    understand the formation of cations in terms of electron loss

    Revise
  5. A.3 b

    understand the formation of anions in terms of electron gain

    Revise
  6. A.4 a

    be able to draw electronic configuration diagrams of cations using dot-and-cross diagrams

    Revise
  7. A.4 b

    be able to draw electronic configuration diagrams of anions using dot-and-cross diagrams

    Revise
  8. A.5 a

    understand reasons for trends in ionic radii down a group

    Revise
  9. A.5 b

    understand reasons for trends in ionic radii for a set of isoelectronic ions such as N3- to Al3+

    Revise
  10. A.6 a

    understand that physical properties of ionic compounds provide evidence for the existence of ions

    Revise
  11. A.6 b

    understand that migration of ions provides evidence for the existence of ions

    Revise
  12. A.7

    know that a covalent bond is the strong electrostatic attraction between two nuclei and the shared pair of electrons between them

    Revise
  13. A.8i

    be able to draw dot-and-cross diagrams to show electrons in covalent substances, including: molecules with single, double and triple bonds

    Revise
  14. A.8ii

    be able to draw dot-and-cross diagrams to show electrons in covalent substances, including: species exhibiting dative covalent (coordinate) bonding, including Al2Cl6 and ammonium ion

    Revise
  15. A.9

    understand the relationship between bond lengths and covalent bond strengths

    Revise
  16. A.10 a

    understand that the shape of a simple molecule is determined by repulsion between electron pairs around a central atom

    Revise
  17. A.10 b

    understand that the shape of a simple ion is determined by repulsion between electron pairs around a central atom

    Revise
  18. A.11 a

    understand reasons for the shape of, and bond angles in, BeCl2

    Revise
  19. A.11 b

    understand reasons for the shape of, and bond angles in, BCl3

    Revise
  20. A.11 c

    understand reasons for the shape of, and bond angles in, CH4

    Revise
  21. A.11 d

    understand reasons for the shape of, and bond angles in, NH3

    Revise
  22. A.11 e

    understand reasons for the shape of, and bond angles in, NH4+

    Revise
  23. A.11 f

    understand reasons for the shape of, and bond angles in, H2O

    Revise
  24. A.11 g

    understand reasons for the shape of, and bond angles in, CO2

    Revise
  25. A.11 h

    understand reasons for the shape of, and bond angles in, PCl5(g)

    Revise
  26. A.11 i

    understand reasons for the shape of, and bond angles in, SF6(g)

    Revise
  27. A.11 j

    understand reasons for the shape of, and bond angles in, related molecules and ions

    Revise
  28. A.11 k

    understand reasons for the shape of, and bond angles in, simple organic molecules in this specification

  29. A.12 a

    be able to predict the shapes of simple molecules analogous to specified examples using electron-pair repulsion theory

    Revise
  30. A.12 b

    be able to predict the bond angles in simple molecules analogous to specified examples using electron-pair repulsion theory

    Revise
  31. A.12 c

    be able to predict the shapes of simple ions analogous to specified examples using electron-pair repulsion theory

    Revise
  32. A.12 d

    be able to predict the bond angles in simple ions analogous to specified examples using electron-pair repulsion theory

    Revise
  33. A.13

    know that electronegativity is the ability of an atom to attract the bonding electrons in a covalent bond

    Revise
  34. A.14 a

    know that ionic and covalent bonding are the extremes of a continuum of bonding type

    Revise
  35. A.14 b

    know that electronegativity differences lead to bond polarity in bonds

    Revise
  36. A.14 c

    know that electronegativity differences lead to bond polarity in molecules

    Revise
  37. A.15 a

    understand that molecules with polar bonds may not be polar molecules

    Revise
  38. A.15 b

    be able to predict whether or not a given molecule is likely to be polar

    Revise
  39. A.16i

    understand the nature of intermolecular forces resulting from the following interactions: London forces (instantaneous dipole – induced dipole)

    Revise
  40. A.16ii

    understand the nature of intermolecular forces resulting from the following interactions: permanent dipoles

    Revise
  41. A.16iii

    understand the nature of intermolecular forces resulting from the following interactions: hydrogen bonds

    Revise
  42. A.17 a

    understand interactions in H2O that give rise to hydrogen bonding

    Revise
  43. A.17 b

    understand interactions in liquid NH3 that give rise to hydrogen bonding

    Revise
  44. A.17 c

    understand interactions in liquid HF that give rise to hydrogen bonding

    Revise
  45. A.18i

    understand the following anomalous properties of water resulting from hydrogen bonding: its relatively high melting temperature and boiling temperature

    Revise
  46. A.18ii

    understand the following anomalous properties of water resulting from hydrogen bonding: the density of ice compared to that of water

    Revise
  47. A.19

    be able to predict the presence of hydrogen bonding in molecules analogous to those mentioned above

    Revise
  48. A.20i

    understand, in terms of intermolecular forces, physical properties shown by materials, including: the trends in boiling temperatures of alkanes with increasing chain length

    Revise
  49. A.20ii

    understand, in terms of intermolecular forces, physical properties shown by materials, including: the effect of branching in the carbon chain on the boiling temperatures of alkanes

    Revise
  50. A.20iii

    understand, in terms of intermolecular forces, physical properties shown by materials, including: the relatively low volatility (higher boiling temperatures) of alcohols compared to alkanes with a similar number of electrons

    Revise
  51. A.20iv

    understand, in terms of intermolecular forces, physical properties shown by materials, including: the trends in boiling temperatures of the hydrogen halides, HF to HI

    Revise
  52. A.21i

    understand factors that influence the choice of solvents, including: water, to dissolve some ionic compounds, in terms of the hydration of the ions

    Revise
  53. A.21ii

    understand factors that influence the choice of solvents, including: water, to dissolve simple alcohols, in terms of hydrogen bonding

    Revise
  54. A.21iii

    understand factors that influence the choice of solvents, including: water, as a poor solvent for compounds (to include polar molecules such as halogenoalkanes), in terms of inability to form hydrogen bonds

    Revise
  55. A.21iv

    understand factors that influence the choice of solvents, including: non-aqueous solvents, for compounds that have similar intermolecular forces to those in the solvent

    Revise
  56. A.22

    know that metallic bonding is the strong electrostatic attraction between metal ions and the delocalised electrons

    Revise