Ignoring or misreading command words — describing when asked to explain, or vice versa
“Take note of the command word used in each question to determine how the examiner expects the question to be answered, for example whether to give a description or an explanation.”— 4PH1 Paper 1P, June 2023 — Paper Summary
How to fix: Before writing anything, underline the command word. 'Describe' means state what is observed — quote data values or name what happens. 'Explain' requires a physical reason — use 'because', 'so', or 'which means' to introduce the mechanism. A description earns 'describe' marks; causation earns 'explain' marks. These are separate mark points and cannot substitute for each other.