Why Is My Child Failing IGCSE Chemistry?

If your child is bringing home failing or sliding chemistry results, the cause is almost never “they’re just not a chemistry person”. In nearly every case it is one of a short list of specific, nameable problems, and each has a different fix. The worst response is to revise harder across everything; the right response is to identify which one is actually yours and attack that. Here is the diagnostic, written for a parent, not a chemist.

The most common cause: understanding the lesson but not the exam

The complaint we hear most often is “my child understands it in class but fails the test.” This feels like a contradiction. It is not. Understanding a lesson and earning marks are two different skills, and 0620 only pays for the second.

The exam never asks “did this make sense when the teacher explained it?” It asks your child to produce an answer from a blank page, in the precise words the Cambridge mark scheme accepts, under time pressure. “The reaction gives off heat” scores nothing where the scheme demands “exothermic”. “The acid gets used up” scores nothing where it wants “hydrogen ions are reduced”. A child can nod through every lesson and still write answers that examiners cannot credit. This is an exam-technique gap, and the good news is it usually fixes faster than a knowledge gap, because the chemistry is already there. The patterns are catalogued in common exam mistakes and decoded further in command words.

The four hard areas where marks actually leak

When a child “fails chemistry”, the losses are almost never spread evenly across the syllabus. They concentrate in four areas, every year, in every school:

1. Moles and stoichiometry. The single biggest mark-loser. The maths is simple, but it chains across four steps, and one early slip poisons the final answer. A child who freezes on calculation questions is usually losing 15 to 20% of the theory paper here alone. The fix is a fixed written layout, drilled. See mole calculations technique and the stoichiometry topic.
2. Electrolysis. The most counterintuitive topic in the course. Which product appears at which electrode depends on three rules at once, and examiner reports flag wrong predictions every single series. Covered under electrochemistry.
3. Organic chemistry. A new language bolted onto the back of the course, taught late in Year 11 when students are tired. See organic chemistry.
4. The practical paper. Worth 20% of the grade and the part schools most often under-teach. A child averaging 80% on theory and 50% here has already spent their A* margin. See the Paper 6 guide.

A child failing chemistry is usually failing two or three of these four, while quietly coping with the rest. The whole map of where difficulty concentrates is in is IGCSE Chemistry hard.

Revising the wrong way: familiarity is not recall

A surprising number of students who “revise for hours” still fail, and the reason is the method, not the effort. Re-reading notes and highlighting feel productive because the material looks familiar by the third pass. Familiarity is the trap. The exam does not test recognition; it tests production from memory. A child who reads the qualitative analysis tables ten times but never tests themselves on them will still blank on the ammonium test in the hall. The fix is active recall and spaced repetition, laid out in how to revise IGCSE Chemistry. If your child revises hard and scores low, suspect the method before the ability.

Falling behind early, then never catching up

Chemistry is cumulative. The mole underpins stoichiometry, which underpins concentration, titration, electrolysis calculations and percentage yield. A child who lost the mole in Year 10 does not have one weak topic; they have a foundation crack that widens through everything built on top. By Year 11 it can look like “failing chemistry” when it is really one untreated Year-10 gap cascading forward. This is why a sliding grade should be diagnosed early, not at the mocks. The parent’s guide to the two-year timeline shows where these cracks usually start.

How to find out which cause is yours

You do not need to understand chemistry to run the diagnosis. You need one piece of evidence: a recent past paper, sat in timed conditions and marked against the real mark scheme, sorted by topic. Then read it like this:

• Marks lost in specific topics (moles, electrolysis, organic) but full marks elsewhere → a knowledge gap in named topics. Target those.
• Right idea written in uncreditable words, lost marks scattered across many topics → an exam-technique gap. Drill command words and mark-scheme phrasing.
• Calculation questions blank or abandoned → a method gap in stoichiometry. Install the four-step layout.
• The practical paper far below the theory papers → an untaught Paper 6. A focused fortnight moves it more than a month moves anything else.
• Hours of revision, low score, no clear pattern → a revision-method gap. Switch from re-reading to active recall.

Most children show two of these, not one. Naming them turns “my child is failing chemistry” into a short, specific to-do list.

What actually fixes it

The wrong fix is “revise harder”, spread evenly, which just reinforces the comfortable topics and starves the broken ones. The right fix is targeted: identify the two or three real gaps, attack them with the matching method, and re-test in two weeks with a fresh paper. For many families that is a self-study project, and the guides linked above are written to run it; the parent-side playbook, including how to help when you do not know chemistry yourself, is in how to help your child with IGCSE Chemistry. For others, the same mistake keeps recurring because no one in the house can see exactly why a mark was lost, and that is the precise point where a specialist earns their fee. The honest decision of whether you are at that point is in does my child need a chemistry tutor.

The reassuring part

A failing chemistry grade in Year 10 or even mid Year 11 is one of the more recoverable academic problems, precisely because the losses are concentrated and the causes are known. The 0620 mark distribution says most of the distance between a failing or B-grade student and an A is two or three weak topics plus exam technique, both fixable inside two terms. If you want that distance measured precisely for your child rather than guessed, a 1-hour trial lesson with a Chemistry specialist will name the actual causes in an hour, and tell you honestly how far the target really is.