O/L — Grade 10 & 11

O/L Science (NIE syllabus)

G.C.E. O/L Science in Sri Lanka follows the National Institute of Education (NIE) syllabus and is taught over Grades 10 and 11 as one subject with three strands — life and life processes, matter and its properties, and energy — with a fourth, earth and space, added in Grade 11. The NIE's Grade 10 guide allocates 165 teaching periods over 20 competency levels (50 in the first term, 64 in the second, 51 in the third); its Grade 11 guide adds 31 more competency levels. This is the Sri Lankan G.C.E. (O/L) syllabus, not Cambridge or Edexcel IGCSE Science.

What the NIE actually examines: Grade 10

These are the NIE's own competency levels and the time it allocates to each. Your school may take them in a different order — the Grade 11 guide calls its sequence 'proposed'.

The NIE's Grade 10 teaching sequence: each competency level, in the term it is taught, with the teaching periods it is given.

Term (NIE)	Level	What it covers	Periods	Source
Grade 10 · Term 1	1.1	The chemical basis of life	10	[S1] p. xii
Grade 10 · Term 1	3.1	Rectilinear motion and graphs of motion	9	[S1] p. xii
Grade 10 · Term 1	2.1	The structure of matter	12	[S1] p. xii
Grade 10 · Term 1	3.2	Newton's laws of motion and the effects of a force	9	[S1] p. xii
Grade 10 · Term 1	3.3	The nature and uses of friction	3	[S1] p. xii
Grade 10 · Term 1	1.2	Plant and animal cell structure under the microscope	7	[S1] p. xii
Grade 10 · Term 2	2.2	The mole, used to quantify elements and compounds	12	[S1] p. xii
Grade 10 · Term 2	1.3	Telling the living from the non-living	5	[S1] p. xii
Grade 10 · Term 2	3.4	The resultant of forces	5	[S1] p. xii
Grade 10 · Term 2	2.3	Properties of compounds and the bonds in them	10	[S1] p. xii
Grade 10 · Term 2	3.5	The turning effect of a force	5	[S1] p. xii
Grade 10 · Term 2	3.6	The conditions of equilibrium	4	[S1] p. xii
Grade 10 · Term 2	1.4	Classifying organisms	12	[S1] p. xii
Grade 10 · Term 2	1.5	Patterns of inheritance of traits	11	[S1] p. xii
Grade 10 · Term 3	3.7	Hydrostatics — sinking, floating and pressure transmission	8	[S1] p. xii
Grade 10 · Term 3	2.4	Chemical changes used to meet needs in life	13	[S1] p. xii
Grade 10 · Term 3	2.5	Controlling the rate of a reaction	5	[S1] p. xii
Grade 10 · Term 3	3.8	Mechanical energy and power	5	[S1] p. xii
Grade 10 · Term 3	3.9	Current electricity and simple circuits	10	[S1] p. xii
Grade 10 · Term 3	1.6	Reproduction and the continuity of organisms	10	[S1] p. xii

Levels, terms and periods from [S1] p. xii: 50 + 64 + 51 = 165 periods. The first digit of a level is its NIE competency: 1 life and life processes, 2 matter and its properties, 3 energy.

What the NIE actually examines: Grade 11

The NIE's Grade 11 sequence adds 31 competency levels, including a fourth competency, earth and space.

Term (NIE)	Level	What it covers	Periods	Source
Grade 11 · Term 1	1.1	The characteristics of plant tissues	4	[S2] p. xvi
Grade 11 · Term 1	1.2	The characteristics of animal tissues	4	[S2] p. xvi
Grade 11 · Term 1	1.3	The importance of photosynthesis	5	[S2] p. xvi
Grade 11 · Term 1	2.1	Types of mixtures	5	[S2] p. xvi
Grade 11 · Term 1	2.2	Expressing the composition of mixtures	5	[S2] p. xvi
Grade 11 · Term 1	2.3	Techniques for separating mixtures	5	[S2] p. xvi
Grade 11 · Term 1	3.1	Mechanical and electromagnetic waves	7	[S2] p. xvi
Grade 11 · Term 1	3.2	Sound waves	4	[S2] p. xvi
Grade 11 · Term 1	3.3	Geometrical optics	12	[S2] p. xvi
Grade 11 · later terms	1.4–1.8	Digestion, respiration, excretion, circulation, co-ordination and homeostasis in humans	4, 5, 3, 5, 5	[S2] pp. xvi-xvii
Grade 11 · later terms	2.4–2.5	Acids, bases and salts; heat changes in chemical reactions	7, 8	[S2] p. xvii
Grade 11 · later terms	2.6–2.8	Electrochemical cells; electrolysis; corrosion	4, 4, 3	[S2] p. xvii
Grade 11 · later terms	2.9–2.10	Hydrocarbons and their derivatives; polymers	3, 3	[S2] p. xvii
Grade 11 · later terms	3.4–3.6	Thermal effects; electrical energy and power; electronics	12, 5, 5	[S2] p. xvii
Grade 11 · later terms	3.7–3.8	Electromagnetic force; electromagnetic induction	5, 4	[S2] p. xvii
Grade 11 · later terms	4.1–4.5	The biosphere and its interactions; ecosystem balance; pollutants; lifestyle change; sustainable development	3, 5, 5, 5, 10	[S2] p. xvii

Levels and periods from [S2] pp. xvi-xvii; the first term is 9 levels and 51 periods. The NIE's published Grade 11 guide is marked DRAFT on every page, and its term column cannot be read after the first term, so the later levels are not split into terms here.

What this site covers today

Nineteen topic pages, grouped by this site, not by the NIE's levels ([S3]). Listed so you can find the page.

Term (this site)	Lesson	Free pages	Source
Grade 10 · Term 1	Matter, Elements and Compounds	Notes · Practice	[S3]
Grade 10 · Term 1	Acids, Bases and the pH Scale	Notes · Practice	[S3]
Grade 10 · Term 1	Plant and Animal Cells	Notes · Practice	[S3]
Grade 10 · Term 2	Photosynthesis	Notes · Practice	[S3]
Grade 10 · Term 2	Digestive, Circulatory, Respiratory and Nervous Systems	Notes · Practice	[S3]
Grade 10 · Term 2	Motion, Force and Newton's Laws	Notes · Practice	[S3]
Grade 10 · Term 3	Forms and Transformations of Energy	Notes · Practice	[S3]
Grade 10 · Term 3	Electricity and Simple Circuits	Notes · Practice	[S3]
Grade 10 · Term 3	Pollution, Climate Change and Conservation	Notes · Practice	[S3]
Grade 11 · Term 1	Chemical Compounds and Equations	Notes · Practice	[S3]
Grade 11 · Term 1	Hydrocarbons and Organic Compounds	Notes · Practice	[S3]
Grade 11 · Term 2	Diodes, Transistors and Simple Circuits	Notes · Practice	[S3]
Grade 11 · Term 2	Heat, Temperature and Heat Transfer	Notes · Practice	[S3]
Grade 11 · Term 2	Waves, Sound and Light	Notes · Practice	[S3]
Grade 11 · Term 2	Plant Structure and Transport in Plants	Notes · Practice	[S3]
Grade 11 · Term 3	Reproduction, Excretion and the Skeletal System	Notes · Practice	[S3]
Grade 11 · Term 3	DNA, Genes and Principles of Heredity	Notes · Practice	[S3]
Grade 11 · Term 3	Ecosystems, Food Chains and Biodiversity	Notes · Practice	[S3]
Grade 11 · Term 3	Past Papers and Model Answers	Notes · Practice	[S3]

Acids, Bases and the pH Scale is one page and is listed once, under Grade 10; the NIE puts acids, bases and salts in Grade 11, level 2.4.

Real past-paper questions, by year

Five year pages cover 2018 to 2023 (2018 and 2019 share one page). Each walks three to five selected questions from a real Department of Examinations paper by number, without reproducing the question text. No year page carries a whole paper.

Year	Page	Source
2018-2019	2018-2019 walkthrough	[S4]
2020	2020 walkthrough	[S4]
2021	2021 walkthrough	[S4]
2022	2022 walkthrough	[S4]
2023	2023 walkthrough	[S4]

Term-by-Term Breakdown

A real past-paper question, worked

Real past-paper question — G.C.E. (O/L) Science 2021, Paper II, Question 5, set by the Department of Examinations. The question is described, not reproduced. · https://doenets.lk/pastpapers

Question 5 gives the universal-indicator colours and pH values a student obtained for four unnamed solutions. It asks you to sort them into acidic, neutral and alkaline, to write the word equation for the neutralisation between the strongest acid and the alkali, and to name one everyday use of an alkali.

Show worked solution

(i) Acidic: A (pH 2) and D (pH 4); Neutral: B (pH 7); Alkaline: C (pH 11). (ii) Acid + Alkali → Salt + Water (i.e. hydrochloric acid + sodium hydroxide → sodium chloride + water). (iii) Toothpaste / baking soda for cooking / lime to neutralise acidic soil (any valid example accepted).

Get your own answer marked

How the exam works

G.C.E. O/L Science is set by the Department of Examinations in two papers. Paper I takes 1 hour: 40 multiple-choice questions at 2 marks each, 80 marks in all — 10 at a basic level, 18 intermediate, 6 higher, and 6 that test analysis, synthesis and evaluation. Paper II takes 3 hours: Part A is 4 compulsory structured questions at 15 marks each (60 marks), with at least a quarter of each question's marks on practical activities; in Part B you answer 3 of 5 semi-structured questions, at 20 marks each (60 marks). ([S5] pp. 08 and 20.)

Department of Examinations — G.C.E. (O/L) 2024 Evaluation Report, Science (Sinhala, PDF)

Where should I start?

One short block per reader, one link each. These are suggestions, not rules; the tables above are the map.

Starting Grade 10 — The NIE's first term opens with the chemical basis of life (level 1.1), then rectilinear motion (3.1). The site's nearest page to the NIE's first level is Cells. → Cells notes
In Grade 11 — Work the real questions we walk, year by year. → 2023 questions
Sitting the examination again — Start from the method, not the first lesson. → How to be ready for O/L Science
Studying in Sinhala → සිංහල
Studying in Tamil → தமிழ்
A parent — What your child gets, and what it costs. → Pricing · For parents

Free study resources by topic

Guides

Questions students ask

How is O/L Science split up?

Into three strands taught across Grades 10 and 11 — life and life processes, matter and its properties, and energy — with a fourth, earth and space, in Grade 11. ([S1] and [S2], syllabus pages)

How much teaching time does Grade 10 Science get?

165 periods over 20 competency levels: 50 in the first term, 64 in the second and 51 in the third. ([S1] p. xii)

Which Grade 10 topics get the most time?

Chemical changes, at 13 periods; then the structure of matter, the mole and classifying organisms, at 12 each. ([S1] p. xii)

Can I practise on real past papers?

Yes — on five year pages covering 2018 to 2023, three to five questions from each paper are walked by number. Not the whole paper: the rest of each paper is not on this site. ([S4])

Is this the same as Cambridge or Edexcel IGCSE Science?

No. This is the Sri Lankan G.C.E. (O/L) syllabus published by the NIE, with its own competencies, its own period weights and its own examination. ([S1] title page)