SEC G2 Science (Physics, Chemistry) is syllabus code K223, and its structure surprises most parents: SEAB writes six papers across the G2 science suite, of which each candidate takes four. K223 candidates sit Papers 1, 2, 3 and 4 for a total of 100 marks. Ancourage Academy teaches G2 science at both centres, and this guide sets out exactly which papers a K223 student sits, how the sessions are timed, why there is no separate practical paper at G2, and what the pairing opens up afterwards. Our secondary science programmes are grouped by pairing rather than by year alone.
The Six-Paper Suite, and Why Candidates Take Four
SEAB builds the three G2 science pairings from one bank of six papers — two per science — and each syllabus code selects the four papers matching its two subjects.
| Paper | Science | Type | Marks | Weighting |
|---|---|---|---|---|
| Paper 1 | Physics | Multiple choice, 20 questions | 20 | 20% |
| Paper 2 | Physics | Structured | 30 | 30% |
| Paper 3 | Chemistry | Multiple choice, 20 questions | 20 | 20% |
| Paper 4 | Chemistry | Structured | 30 | 30% |
| Paper 5 | Biology | Multiple choice, 20 questions | 20 | — |
| Paper 6 | Biology | Structured | 30 | — |
A K223 candidate sits Papers 1, 2, 3 and 4 — the Physics and Chemistry pairs — and does not sit Papers 5 and 6, which belong to Biology. The other two pairings select differently: K224 (Physics, Biology) takes Papers 1, 2, 5 and 6, and K225 (Chemistry, Biology) takes Papers 3, 4, 5 and 6.
This selection design is the thing most commonly misunderstood. A student is not sitting six papers, and the paper numbers are fixed to the science rather than to the order in which they are taken. Paper 3 is always Chemistry multiple choice, whichever pairing a candidate is entered for.
How the Papers Are Timed
SEC G2 Science (Physics, Chemistry), K223, pairs Physics Papers 1 and 2 in one session of 1 hour 15 minutes and Chemistry Papers 3 and 4 in another, with candidates advised not to spend more than 30 minutes on the multiple-choice Papers 1 and 3.
That advisory is the whole exam-technique problem in one sentence. The multiple-choice half and the structured half share one clock. A candidate who spends 45 minutes on 20 multiple-choice questions has taken the time away from a structured paper worth half as much again.
- Session A — Papers 1 and 2 (Physics): 1 hour 15 minutes total. Aim to leave Paper 1 at the 30-minute mark whether or not every question feels settled.
- Session B — Papers 3 and 4 (Chemistry): same 1 hour 15 minute structure, same 30-minute advisory on Paper 3.
- Marks favour the structured half. Each structured paper is worth 30 marks against the multiple-choice 20. Under the advised split the rate is the same either way — 20 marks in 30 minutes and 30 marks in the remaining 45 both come to two-thirds of a mark a minute — so the cost of overrunning is that it eats the higher-scoring paper.
- Practise the pair, not the paper. Sitting Paper 2 alone never rehearses the decision that actually costs marks.
Why There Is No Separate Practical Paper at G2
G2 science has no standalone practical examination. Practical work is expected during the course — SEAB sets a practical list for each component science and expects at least four tasks from each, so a Physics and Chemistry candidate does at least eight in total — and experimental skills and investigations are assessed inside the theory papers, carrying approximately 10% of the marks.
This is a real difference from the G3 route, and it is worth stating precisely because it is easy to get backwards. At G3, Combined Science (syllabuses K326, K327 and K328) is examined with a separate Paper 5 practical assessment covering both component sciences. At G2, no such paper exists, and the number 5 refers instead to the Biology multiple-choice paper in the six-paper suite.
The practical consequence for revision is that experimental questions cannot be skipped as "the practical bit". Roughly a tenth of the marks in the written papers test apparatus, variables, procedure, sources of error and interpretation of results. Our science practical preparation guide covers the underlying skills, which transfer directly to written experimental questions.
Who the Physics and Chemistry Pairing Suits
K223 is the physical-sciences pairing, and it suits students heading towards engineering, built environment, applied physical science and most technology diplomas.
- Mathematical comfort helps. Both halves of K223 are calculation-heavy relative to Biology, so a student who is coping with G2 Mathematics will find the pairing more comfortable.
- Shared habits of thought. Physics and Chemistry both reward unit discipline, formula selection and working shown line by line — the study method transfers between the two halves.
- No Biology content at all. A student with a strong interest in health or life sciences is usually better served by K224 or K225.
- It is a full science subject. The pairing is not a reduced option; it is two sciences examined at the G2 standard.
Our guide to Combined Science versus Pure Science covers the wider choice, and the Sec 3 subject combination guide covers when the decision is actually made.
How K223 Differs from the G3 Route
The G3 equivalent, K326, is a different examination: four papers including a practical assessment, 200 marks in total, examined at the former O-Level standard.
| Aspect | G2 Science, Physics and Chemistry (K223) | G3 route (K326) |
|---|---|---|
| Papers sat | Four, selected from a six-paper suite | Four, including a practical assessment |
| Total marks | 100 | 200 |
| Practical examination | None — assessed within the theory papers | Yes, a separate practical assessment |
| Session structure | Paired papers, 1h 15min per pair | Separate papers |
| Exam standard | Former N(A)-Level standard | Former O-Level standard |
| Counts for JC L1R4 | No | Yes |
Our G2 vs G3 subject levels guide explains how a level is chosen and reviewed under Full Subject-Based Banding, and the SEC replaces the O-Level for G3 subjects from 2027.
Where a K223 Grade Counts Afterwards
G2 science grades appear on the SEC certificate and count towards polytechnic and Polytechnic Foundation Programme routes, but every subject in a junior college or Millennia Institute aggregate from 2028 must be taken at G3.
MOE states on its JC and MI admission criteria page that "All subjects used in aggregate score computation for JC and MI admissions must be taken at G3." For a student aiming at an engineering or technology diploma, that is not a constraint that bites — the science pairing is relevant preparation and the grade counts on the polytechnic side. Our post-secondary pathways guide sets out those routes.
A Revision Plan Built Around the Paired Sessions
Because the papers are examined in pairs under one clock, revision should rehearse the pair rather than the individual paper.
- Weekly: one timed pair — either Papers 1 and 2, or Papers 3 and 4 — with a hard stop at 30 minutes on the multiple-choice half.
- Track the two sciences separately. A student can be strong in Chemistry and weak in Physics and still show a middling overall mark that hides the imbalance.
- Drill experimental questions deliberately. Around a tenth of the marks sit there, and they are the easiest to leave unrevised.
- Build a formula and definition sheet per science. Recall failures in a structured paper are usually definition failures.
- Analyse errors by type. Our guide to using past-year papers effectively sets out a workable routine.
Where science sits near a promotion threshold, our guide to how promotion into Sec 4 is decided explains how subject marks are counted, and a trial class (usually $18) starts with a timed paired session.
Common Questions About SEC G2 Science (Physics, Chemistry)
What is the syllabus code for G2 Science with Physics and Chemistry?
It is K223, listed by SEAB among the G2 Cambridge subjects as "Science (Physics, Chemistry)". The other two G2 science pairings are K224, Science (Physics, Biology), and K225, Science (Chemistry, Biology).
How many papers does a K223 candidate sit?
Four. SEAB writes six papers across the G2 science suite — two for each of Physics, Chemistry and Biology — and each syllabus code selects the four matching its two sciences. A K223 candidate sits Papers 1 and 2 for Physics and Papers 3 and 4 for Chemistry, totalling 100 marks.
How long is each G2 science session?
For the SEC G2 Science pairings K223, K224 and K225, each component science's two papers are sat together in one session of 1 hour 15 minutes. Candidates are advised not to spend more than 30 minutes on the multiple-choice half of each pair. Since the structured half carries 30 marks against the multiple-choice 20, overrunning on multiple choice is the most common way to lose marks.
Is there a practical examination in G2 Science?
No. G2 science has no separate practical paper. Practical work is expected during the course, with at least four practical tasks expected from each component science’s own list — eight for any pairing, Physics and Chemistry in the case of K223 — and experimental skills and investigations are assessed inside the written theory papers, carrying approximately 10% of the marks. This differs from the G3 route, where syllabuses K326, K327 and K328 include a separate practical assessment.
Can a G2 science grade be used for junior college admission?
No. MOE requires every subject used in the aggregate for junior college and Millennia Institute admission from 2028 to be taken at G3. A G2 science grade still appears on the SEC certificate and still counts towards polytechnic and Polytechnic Foundation Programme routes.