How a six-mark chemistry question is actually marked

Marked twice

Most questions on a chemistry paper are marked by points. The scheme lists the creditable statements, the examiner ticks the ones on the page, and the marks are the ticks. A six-mark extended-response question is marked differently, and the difference is the whole reason so many answers full of correct chemistry score three.

The examiner reads the whole answer first and decides which level it belongs to, from the shape of the reasoning rather than from any one fact in it. Only then do they decide the mark within that level, from how much of the indicative content, the list of chemistry the question was looking for, the answer contains. Two marks per level, three levels, six marks. The level is a judgement about how the answer is put together; the mark inside it is a count.

That order matters. An answer that contains every fact on the indicative content list as a heap of unconnected sentences is capped at the level its shape earns, however much it knows.

What the levels mean

In plain terms: Level 1 is relevant chemistry with no chain between the statements. Level 2 is mostly relevant chemistry with some of the links made and some of the precision. Level 3 is a line of reasoning: clear, precise, and connected, so that each point follows from the one before and the reader could not reorder the sentences without breaking the argument. The examiners’ own description of a strong answer, from the June 2023 report, is worth quoting because it is also the instruction.¹

Read it as a list of three separate demands. Sequence is the level. Precise is the mark scheme word, the same rule that runs through every other question on the paper. Ticking off the indicative content is the mark within the level. An answer can fail on any one of the three independently.

What the examiners saw

The June 2023 Paper 3 six-marker asked students to explain why one iron solution effervesced with carbonate and another did not. The report records that “only about 10% of students were able to access level 3”, the same as the previous year, and it says why: the commonest omissions were the two indicative-content points that gave the reason. “Many students thought that it was enough to simply say that CO₂ is produced with L but not M and did not go on to discuss the reasons for this in terms of the greater acidity of Fe³⁺(aq) compared with Fe²⁺(aq).”¹

That is the level ceiling in action. Stating what happens is a point. Explaining why it happens is the link that turns the points into a sequence, and without it the answer cannot leave Level 2 however many other true things it says. The general comments make the same diagnosis in one clause: relatively few reached Level 3, “usually due to a failure to properly describe a reason”.¹

The other way to lose the top marks is to reach the level and then contradict yourself inside it. The June 2018 Paper 2 report, on the benzene six-marker, records that Level 3 answers were written by 15.3% of students, and that only a third of those gained full marks, because “their explanations often contained errors such as ‘hydration’ for hydrogenation, or unclear discussion about bond breaking during the addition of hydrogen”.² The shape earned Level 3. The precision inside it did not earn six.

Right plus wrong equals wrong

That last ruling is the general rule showing through, and it is the one students least expect. The levels system does not deduct for small weaknesses inside an otherwise strong answer; the examiner finds the band whose description fits best and does not go hunting for reasons to drop it. But the indicative content still binds at the top. Full marks need an answer with no incorrect statement contradicting a correct one, and a wrong word placed next to the right chemistry is exactly such a statement.

So the safest six-mark answer is not the longest. Every extra sentence is another chance to write “hydration” where “hydrogenation” was meant, and an extra true sentence adds nothing once the content is covered. Write the sequence, write it precisely, and stop.

How to write one

1. Find the question in the question. A six-marker nearly always asks you to explain a difference or a change. Name the two things being compared before you write anything else, and make sure your answer explains why they differ, not only that they do.
2. Write the chain, not the pile. Each sentence should be a consequence of the one before. “Because”, “so”, and “therefore” are not padding here; they are the links the level is decided on. The report says a list layout is not appropriate, and the reason is that a list has no links in it.
3. Use the paper’s own words. The indicative content is written in the specification’s vocabulary. The mark inside the level is a count of those words, correctly used.
4. Include the reason for every observation. “CO₂ is produced with L and not M” is the observation. The acidity of the hexaaqua ion that makes it happen is the reason, and the reason is the mark most answers were missing.
5. Stop when the content is covered. A wrong extra sentence can cost a mark; a right extra sentence cannot earn one.

One honest note on what this post is. The mechanics of levels marking are described here in our own words from the boards’ published instructions to examiners; the quotations are from two AQA reports, and the claims about what examiners saw are about those two papers. Other boards use the same structure with their own descriptors, and the safe reading is that the shape of a good answer is the same everywhere and the exact wording of each level is the board’s own.