Count carbon skeleton with functional group
A displayed formula in a fertiliser label discussion shows \(5\) carbon atoms and the highlighted C=C group. Enter the carbon count used for the parent chain. Read the diagram labels first, then answer with the classification or value. Enter the answer and choose the interpretation that matches the chemistry.
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.