Edexcel International A Level Chemistry Topic 3B/3C banner showing water methane and ammonia molecular shapes with bond angles 104.5 109.5 and 107 degrees

Covalent Bonding and Shapes of Molecules – Topic 3B/3C

£34.99

Associated Courses

Covalent Bonding and Shapes of Molecules Topic 3B/3C

The Topic 3B/3C course on Edexcel International A Level Chemistry provides approximately 14 hours of guided learning. Students work through three recorded video lessons, 94 marks of auto-marked MCQ practice, 180 marks of teacher-marked written questions, and a personalised spec-point progress report.

Guided Learning
14 Hours
total study time
Video Lessons
281 mins
3 recorded lessons
MCQ Assessments
94 Marks
5 quizzes
SAQ Assessments
180 Marks
6 quizzes

How the 14 guided learning hours are worked out

Guided learning hours are calculated from the actual contents of the course, not estimated. Video time is counted at its true running length, MCQs at 1.5 minutes per question, written answers at 1.5 minutes per mark, and time is allowed for reading the feedback returned on every quiz.

ComponentTime
Virtual lesson video281 min
MCQ practice (94 questions × 1.5 min)141 min
MCQ feedback review (5 quizzes × 10 min)50 min
SAQ practice (180 marks × 1.5 min)270 min
SAQ feedback review (6 quizzes × 15 min)90 min
Total832 min ≈ 14 hours

The three recorded lessons

The virtual lesson is delivered as three recorded lessons totalling 281 minutes. Students pause during exam-practice sections, attempt questions independently, then review the worked explanations and the mark-scheme approach.

LessonRunning time
1. Covalent Bonding78 min
2. Shapes of Molecules121 min
3. Exam Practice82 min
Total video281 min

Course preview

A short walkthrough of how the course is taught and how the assessment fits together.

At a glance

What you get in this course

281 minutes of guided video

Three recorded lessons covering Topic 3B and Topic 3C in full, with worked exam questions and mark-scheme strategy built into the teaching.

94 marks of MCQ practice

5 auto-marked quizzes of 17–21 questions each, with diagnostic feedback on every option. One attempt per quiz, so your scores track real progress.

180 marks of written practice

6 written-answer quizzes (78 questions) marked by a chemistry specialist, with per-mark feedback returned the following Monday.

Complete spec-point coverage

39 Edexcel IAL spec points are assessed in this course, every one of them in both question styles.

Exam-technique baked in

The lessons teach the chemistry and the exam wording. You learn what Edexcel actually rewards, not just the content.

Personalised progress report

A one-click PDF report shows your level on every spec point in colour-coded form.

What is KASP Analytics?

KASP (Knowledge Analytics & Spec-point Platform) tracks your progress at the level of individual specification points, not just whole quizzes. Every question on this course is mapped to the Edexcel IAL spec point it assesses, so you always know exactly which parts of the specification you have mastered and which need another look.

Spec points tracked
39
Specification area
Topic 3: Bonding and Structure
Questions tagged
172
39 spec points assessed in this course

Topic 3 Bonding and Structure is split across two courses: this one covers the covalent bonding and molecular shapes half, and Topic 3A/3D covers ionic and metallic bonding. Between them the two courses assess all 61 Topic 3 spec points. Across the 94 MCQ and 78 SAQ questions here, most of those spec points are assessed several times over, in both question styles.

Your topic dashboard

Every topic you have worked through is summarised here. At a glance you see how many questions you have attempted, what is still waiting to be marked, your total marks scored, and an overall score percentage. The dashboard below is an example, filled with the real topic structure of this course.

Hello, Sara – here is how you are doing

Edexcel IAL Chemistry
TopicQuestions attemptedPendingMarks (scored / available)Score
Topic 3B: Covalent Bonding22 / 28436.00 / 50.0072%
Topic 3C: Shapes of Molecules19 / 26527.50 / 46.0060%

Spec-point breakdown for a topic

Click into any topic and you see the full spec-point breakdown. Each row is a single Edexcel IAL spec point with its official wording, how many questions the bank holds against it, your score, and a colour that tells you immediately where to focus. The spec points and question counts below are the real ones from this course; the scores are an example.

Spec tagDescriptionAttemptedIn bankMarksScore
3.11ibe able to draw dot-and-cross diagrams to show electrons in covalent substances, including: molecules with single, double and triple bonds4 / 498.00 / 8.00100.0%
3.11iibe able to draw dot-and-cross diagrams to show electrons in covalent substances, including: species with dative covalent (coordinate) bonds, including Al2Cl6 and the ammonium ion5 / 5119.00 / 11.0081.8%
3.15-abe able to distinguish between polar bonds and polar molecules3 / 3105.00 / 6.0083.3%
3.15-bbe able to predict whether or not a given molecule is likely to be polar4 / 4236.00 / 9.0066.7%
3.18-dknow and be able to explain the shape of, and bond angle in, NH35 / 5127.00 / 12.0058.3%
3.18-eknow and be able to explain the shape of, and bond angle in, NH4+3 / 4104.00 / 8.0050.0%
3.18-fknow and be able to explain the shape of, and bond angle in, H2O2 / 3132.00 / 7.0028.6%
3.19-abe able to apply electron-pair repulsion theory to predict the shapes of molecules and ions analogous to those in 3.180 / 313–Not yet attempted
■ Green 70–100%: secure mastery■ Orange 40–69%: some gaps■ Red 0–39%: needs attention■ Grey: not yet assessed

Printable progress report

One click and you can download a clean, branded Progress Report PDF for the topic. Useful for your own revision folder, for parents to see at a glance, or for tutors to plan focused sessions. Every spec point in the topic appears with its code and full requirement text, and the level column is colour-coded green through red.

A Level Chemistry progress report for Covalent Bonding and Shapes of Molecules showing student performance across specification points with colour coded levels for understanding
At a glance

What you get with KASP Analytics

Spec-point level tracking

Every question is tagged to the exact Edexcel IAL spec point it assesses, so your scores roll up cleanly to the specification.

Updates automatically

Submit a quiz and your dashboard updates right away. Short-answer questions appear as pending until they have been marked.

Built for Edexcel IAL

Wording, codes and topic structure follow the Edexcel International A Level Chemistry specification exactly, so your scores line up with the document you will be examined on.

Printable report

One-click PDF Progress Report per topic, in the same colour system, ready for your folder or for a tutor session.

Both question styles counted

MCQ and written answers feed the same spec point. With 94 MCQ and 78 SAQ questions tagged, a weak area shows up whether you miss it under multiple choice or in writing.

Progress over time

A simple line chart shows how your overall score has trended across the days you have been studying.

What is the MCQ Bank?

The MCQ Bank for Topic 3B/3C is an auto-marked, instant-feedback practice engine built from past Edexcel IAL paper questions. It runs to 5 quizzes, 94 questions and 94 marks. Every question is tagged to a specific Edexcel IAL spec point, every option carries diagnostic feedback explaining the chemistry, and every quiz attempt feeds directly into your KASP Analytics dashboard.

Quizzes
5
Questions
94
Marks
94
Attempts
1 per quiz

Try a real Topic 3B/3C MCQ

This is a genuine question from the bank, reproduced exactly as it appears in the course. Click any option to reveal the diagnostic feedback for that choice, then expand the panel at the bottom for the full walkthrough.

Identifying the polar molecule

3.15-b (Edexcel IAL)1 mark

Which molecule is polar?

Click an option to see feedback

ANH3(g)
Correct

Correct. NH3 is pyramidal due to a lone pair on nitrogen. The N-H bond dipoles do not cancel and the lone pair contributes to the overall asymmetry, giving NH3 a permanent dipole moment.

BBeCl2(g)
Incorrect

Incorrect. Although BeCl2 has polar Be-Cl bonds, the molecule is linear. The two bond dipoles point in exactly opposite directions and cancel, so BeCl2 has no net dipole and is non-polar.

CSF6(g)
Incorrect

Incorrect. Although SF6 has six polar S-F bonds, the molecule is octahedral with perfect symmetry. The six bond dipoles cancel out in all directions, giving no net dipole. SF6 is non-polar.

DCO2(g)
Incorrect

Incorrect. Although CO2 has polar C=O bonds, the molecule is linear. The two bond dipoles point in exactly opposite directions and cancel out, so CO2 has no net dipole and is non-polar.

Show correct answer & full explanation →
General feedback

A molecule is polar if it has polar bonds and those bonds do not cancel out due to molecular symmetry. A lone pair on the central atom typically causes an asymmetric shape that results in a net dipole.

  • BeCl2(g): has two polar Be-Cl bonds, but the molecule is linear. The two dipoles point in exactly opposite directions and cancel, so BeCl2 is non-polar.
  • SF6(g): has six polar S-F bonds, but the molecule is octahedral with perfect symmetry. All six bond dipoles cancel, so SF6 is non-polar.
  • CO2(g): has two polar C=O bonds, but the molecule is linear. The dipoles point in opposite directions and cancel, so CO2 is non-polar.
  • NH3(g): has three polar N-H bonds and a lone pair on nitrogen, giving a pyramidal shape. The bond dipoles do not cancel, and the lone pair adds to the asymmetry. NH3 has a net dipole and is polar.

The correct answer is NH3(g).

5 quizzes, 94 marks of MCQ practice

The MCQ Bank is split across the two halves of the topic. Quizzes hold 17–21 questions worth one mark each, and each quiz is a single auto-marked attempt. Because every spec point is tested across several quizzes, your KASP scores reveal real improvement as you work through them.

Topic 3B: Covalent Bonding

3 quizzes · 52 marks
MCQ A
18
questions & marks
MCQ B
17
questions & marks
MCQ C
17
questions & marks

Topic 3C: Shapes of Molecules

2 quizzes · 42 marks
MCQ A
21
questions & marks
MCQ B
21
questions & marks
94 total marks94 questions in totalOne attempt per quizAuto-marked on submit
At a glance

What you get with the MCQ Bank

94 marks across 5 quizzes

3 quizzes on Topic 3B and 2 on Topic 3C, 17–21 questions each, giving balanced coverage across the whole topic.

Instant auto-marking

Submit and the result is back in your hands inside a second. No waiting, no manual checking.

Diagnostic feedback per option

Every wrong option carries a tailored explanation of the misconception, not just a generic ‘incorrect’, plus a full walkthrough on every question.

Spec-point tagged

Each question is mapped to the Edexcel IAL spec point it assesses, so your score flows straight into KASP Analytics.

Track improvement across quizzes

One attempt per quiz, but the same spec points appear across the set. Your scores from quiz to quiz show genuine progress, not repeat-attempt inflation.

Built from past papers

Every MCQ is sourced from genuine Edexcel IAL past papers, with the wording polished for clarity and the chemistry verified.

What is the SAQ Bank?

The SAQ Bank for Topic 3B/3C is a written-answer practice engine marked by a real chemistry specialist. It runs to 6 quizzes, 78 questions and 180 marks. You attempt one quiz per week, submit your full written response, and your teacher returns mark-by-mark feedback the following Monday. Every comment is targeted at the exam wording you need to use.

Quizzes
6
Questions
78
Marks
180
Marks per quiz
30

A submitted SAQ and the feedback it gets

This is a genuine question from the bank with its real mark scheme. The submitted answer below is an example of a typical response at this standard. Expand the panel to see how it was marked.

Bond angles and shapes of water and the oxonium ion

3.18-f (Edexcel IAL)4 marks

Oxonium salts contain the oxonium ion, H3O+. This ion is formed when water forms a dative covalent bond with a proton.

Explain, using electron-pair repulsion theory, how the water molecule and the oxonium ion have different bond angles and shapes.

Submitted answer

In water the oxygen atom has two bonding pairs and two lone pairs, which makes the molecule bent with a bond angle of 104.5°. In the oxonium ion the oxygen has three bonding pairs and one lone pair, so it is trigonal pyramidal with a bond angle of 107°.

View returned feedback →
Returned by your chemistry specialist3 / 4 · 75%
Mark scheme
Criterion
✓Bond angles: 104.5 degrees in water and 107 degrees in the oxonium ion.
Awarded – both angles quoted correctly, and to the precision the mark scheme expects.
✓Shapes: bent / V-shaped for water and (trigonal) pyramidal for the oxonium ion.
Awarded – both shapes named correctly.
✓Water has two bonded pairs (of electrons) plus two lone pairs and the oxonium ion has three bonded pairs plus one lone pair.
Awarded – the electron-pair counts are right for both species.
✗Lone pairs repel more (than bonded pairs, and water has more lone pairs, so the bond angle is smaller in water / the shape changes).
Not awarded. You gave the shapes and the angles but never said why they differ. The mark needs the repulsion argument: lone pairs repel more strongly than bonding pairs, and water has two lone pairs to the oxonium ion's one, so the bond angle in water is squeezed further.
Teacher comment

Three marks banked cleanly, Sara – the shapes, the angles and the electron-pair counts are all correct, which is more than most students manage on this question. The mark you have missed is the one the question is really testing: it says ‘using electron-pair repulsion theory’, so the examiner wants the comparison, not just the description. Add one sentence – lone pairs repel more than bonding pairs, and water has an extra lone pair, so its angle is smaller – and this is a full-mark answer.

A predictable weekly rhythm over 6 weeks

One quiz per week across the 6 quizzes, so the SAQ Bank runs as a 6-week programme. Submit anywhere from Monday to Friday, marking happens over the weekend, and you receive your feedback by the following Monday. The rhythm is the same every week so you always know when to expect a return.

Mon
Submit
Tue
Submit
Wed
Submit
Thu
Submit
Fri
Submit
Sat
Marking
Sun
Marking
Mon
Returned

One attempt per quiz, one quiz submitted per week. Because the same spec points reappear across the 6 quizzes, your scores over the programme show genuine improvement – not repeat-attempt inflation. The weekly cap also keeps the marking load manageable so your feedback stays genuinely thorough.

6 quizzes, 180 marks of written practice

The SAQ Bank holds 78 questions and 180 marks between its 6 quizzes. Every quiz is worth 30 marks, and runs to between 11 and 16 questions depending on how the marks fall, with the parts of any one original exam question kept together in the same quiz. They draw from past Edexcel IAL written-paper questions across the whole topic pair.

Topic 3B: Covalent Bonding

3 quizzes · 90 marks
SAQ A
30
marks · 14 questions
SAQ B
30
marks · 14 questions
SAQ C
30
marks · 16 questions

Topic 3C: Shapes of Molecules

3 quizzes · 90 marks
SAQ A
30
marks · 12 questions
SAQ B
30
marks · 11 questions
SAQ C
30
marks · 11 questions
180 total marks78 questions1 quiz per week, over 6 weeksReturned the following Monday

What the written questions ask you to do

The bank is not all prose. Alongside written explanations you are asked to draw structures and mechanisms and to work through calculations, all marked by hand against the same mark scheme.

Question styleQuestionsWhat it asks for
Written answer57Explanations, descriptions, equations and definitions, marked against the exam mark scheme point by point.
Drawing21Structural and displayed formulae, skeletal structures and mechanism steps, drawn on screen and marked by the specialist.
Total78
At a glance

What you get with the SAQ Bank

180 marks across 6 quizzes

3 quizzes on Topic 3B and 3 on Topic 3C, holding 78 questions between them at 30 marks per quiz.

Marked by a chemistry specialist

Not auto-graded, not AI-scored. A subject specialist reads your answer end-to-end and writes the comments by hand.

Per-mark feedback

Every mark in the scheme is checked off explicitly. You see exactly which marks you earned and what wording the missed ones needed.

Predictable weekly turnaround

Submit by Friday, marked over the weekend, feedback returned by Monday. One quiz per week; one attempt per quiz; 6 weeks end to end.

Exam-board wording focus

Feedback teaches the precise language the Edexcel mark scheme rewards, so the next time the topic appears you write to score.

Feeds your KASP dashboard

Every SAQ is spec-point tagged. Once marked, your scores flow into KASP Analytics alongside your MCQ results.

Exam Board Alignment

Covalent Bonding and Shapes of Molecules Topic 3B/C Edexcel International

This course covers the following Edexcel International A Level Chemistry specification points:

3.10
understand that covalent bonding is the strong electrostatic attraction between two nuclei and the shared pair of electrons between them, based on the evidence:
i
the physical properties of giant atomic structures
ii
electron density maps for simple molecules
3.11
be able to draw dot-and-cross diagrams to show electrons in covalent substances, including:
i
molecules with single, double and triple bonds
ii
species with dative covalent (coordinate) bonds, including Al₂Cl₆ and the ammonium ion
3.12
be able to describe the different structures formed by giant lattices of carbon atoms, including graphite, diamond and graphene, and discuss the applications of each
3.13
understand the meaning of the term ‘electronegativity’ as applied to atoms in a covalent bond
3.14
know that ionic and covalent bonding are the extremes of a continuum of bonding type and be able to explain this in terms of electronegativity differences, leading to bond polarity in bonds and molecules, and to ionic bonding if the electronegativity is large enough
3.15
be able to distinguish between polar bonds and polar molecules and predict whether or not a given molecule is likely to be polar
Practical
Further suggested practical: Determine the effect of an electrostatic force on jets of liquids (water, ethanol and cyclohexane) and use the results to determine whether the molecules are polar or non-polar
3.16
understand the principles of the electron-pair repulsion theory, used to interpret and predict the shapes of simple molecules and ions
3.17
understand the terms ‘bond length’ and ‘bond angle’
3.18
know and be able to explain the shapes of, and bond angles in, BeCl₂, BCl₃, CH₄, NH₃, NH₄⁺, H₂O, CO₂, gaseous PCl₅, SF₆ and C₂H₄
3.19
be able to apply the electron-pair repulsion theory to predict the shapes of, and bond angles in, molecules and ions analogous to those in 3.18
Specification Coverage

Students will be assessed on their ability to:

The following specification points outline the knowledge and skills students are expected to demonstrate.

3.10
understand that covalent bonding is the strong electrostatic attraction between two nuclei and the shared pair of electrons between them, based on the evidence:
i
the physical properties of giant atomic structures
ii
electron density maps for simple molecules
3.11
be able to draw dot-and-cross diagrams to show electrons in covalent substances, including:
i
molecules with single, double and triple bonds
ii
species with dative covalent (coordinate) bonds, including Al2Cl6 and the ammonium ion
3.12
be able to describe the different structures formed by giant lattices of carbon atoms, including graphite, diamond and graphene, and discuss the applications of each
3.13
understand the meaning of the term ‘electronegativity’ as applied to atoms in a covalent bond
3.14
know that ionic and covalent bonding are the extremes of a continuum of bonding type and be able to explain this in terms of electronegativity differences, leading to bond polarity in bonds and molecules, and to ionic bonding if the electronegativity is large enough
3.15
be able to distinguish between polar bonds and polar molecules and predict whether or not a given molecule is likely to be polar
3.16
understand the principles of the electron-pair repulsion theory, used to interpret and predict the shapes of simple molecules and ions
3.17
understand the terms ‘bond length’ and ‘bond angle’
3.18
know and be able to explain the shapes of, and bond angles in, BeCl2, BCl3, CH4, NH3, NH4+, H2O, CO2, gaseous PCl5, SF6 and C2H4
3.19
be able to apply the electron-pair repulsion theory to predict the shapes of, and bond angles in, molecules and ions analogous to those in 3.18
Complete Topic Package

Learn the content, practise exam questions, and identify exactly where marks are being lost.

This course combines guided video teaching, diagnostic MCQs, teacher-marked written assessment, and detailed specification reporting for Edexcel International A Level Chemistry.

Exam-focused learning with clear performance feedback

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