Ask a chemistry student what they fear most in the exam and many will say the same thing: the 6‑mark question. That big empty box, worth a chunk of the paper, where you’re expected to “write everything you know.”
Here’s the reassuring truth from someone who marks these questions: 6‑mark answers follow a pattern. They aren’t a memory dump — they’re a structured argument. Learn the structure and they become some of the most reliable marks on the paper.
Why students lose marks (even when they know the chemistry)
As an examiner, the most common mistakes I see aren’t gaps in knowledge — they’re gaps in technique:
- Writing everything they know about the topic instead of answering the question asked.
- Missing the command word (explain, describe, compare, evaluate — each wants something different).
- Vague language where the mark scheme demands precise terms.
- No logical order, so the examiner can’t follow the reasoning.
- Forgetting to actually conclude on an “evaluate” or “compare” question.
Fix these and your mark jumps — no extra revision required.
Step 1 — Decode the command word
The command word tells you what kind of answer earns marks:
| Command word | What it wants | |—|—| | Describe | Say what happens (facts, no reasons needed) | | Explain | Say why it happens (cause → effect) | | Compare | Give similarities and differences, ideally point‑by‑point | | Evaluate | Weigh pros and cons and give a judgement/conclusion | | Suggest | Apply your knowledge to an unfamiliar situation |
If the question says explain and you only describe, you cap your own marks. Underline the command word before you write a single sentence.
Step 2 — Plan for 30 seconds
Don’t start writing immediately. Jot 4–6 quick bullet points of the ideas you’ll cover, in a logical order. This tiny investment stops you rambling, repeating yourself, or forgetting a key point halfway through.
Six marks usually means the examiner is looking for roughly six creditworthy points — so aim for at least that many distinct ideas in your plan.
Step 3 — Write in a logical chain
Mark schemes reward linked reasoning, especially for “explain” questions. Build a cause‑and‑effect chain:
Because [X]… this causes [Y]… which results in [Z].
For example, explaining why giant covalent structures have high melting points:
“Diamond has many strong covalent bonds between its carbon atoms (point 1). A large amount of energy is needed to break these bonds (point 2). Therefore it has a very high melting point (point 3).”
Three clean, linked points — three marks — in two sentences. No waffle.
Step 4 — Use precise chemical vocabulary
This is where exam‑board precision matters. “The particles stick together” won’t score; “there are strong electrostatic forces of attraction between oppositely charged ions” will. The mark scheme lists the exact terms it wants — and as an examiner, I can only award what’s on it. Use the proper words: electrostatic, intermolecular, delocalised, exothermic, equilibrium, oxidised — whatever the topic demands.
Step 5 — Conclude when asked
For evaluate and compare questions, the final mark is often the conclusion. After weighing both sides, commit: “Overall, method A is better because…” Students routinely lay out all the evidence and then forget to give the judgement — throwing away the easiest mark in the question.
A quick model (GCSE example)
Q: Explain why metals conduct electricity. (6 marks)
Metals have a giant structure of positive ions (1) arranged in a regular lattice, surrounded by a “sea” of delocalised electrons (2). These delocalised electrons are free to move throughout the structure (3). When a voltage is applied (4), the electrons move in one direction (5), and this flow of charge is an electric current (6).
Six linked points, precise vocabulary, logical order. Full marks.
The bottom line
A 6‑mark chemistry answer is a structured argument, not a brain dump:
- Decode the command word.
- Plan 4–6 points for 30 seconds.
- Write a logical, linked chain.
- Use precise chemical vocabulary.
- Conclude when the question asks you to.
Practise this method on past‑paper extended questions and mark yourself against the official mark scheme. You’ll be amazed how quickly these go from your most‑feared to your most‑reliable marks.
Want me to mark your extended answers the way a real examiner would, and show you exactly where the marks are? That’s part of what I do in every lesson.
👉 Book a free intro call and let’s turn 6‑mark questions into your strong suit.