Dominant uncertainty source
A propagated-uncertainty table in a school extension laboratory shows one instrument contributes 8% while other sources contribute 1% and 2%. Identify the best improvement target. Enter the answer and choose the interpretation that matches the HL chemistry evidence.
Worked practice: chemistry evidence and answer
Use the chemical evidence first, then enter the result and interpretation that match it.
Write a full answer
Now write the response in full, in your own words — this is what the exam asks for. The AI marks it on the same moves you built above (focus, evidence, technique, judgement) and gives feedback on reasoning, evidence, and expression.