Command Words in Chemistry

Command words tell you exactly what the examiner expects. Misreading a command word is one of the most common reasons students lose marks — not because they lack knowledge, but because they answer a different question from the one being asked.

---

The Key Command Words

State / Give / Name

These require a brief, factual answer — often a single word, phrase, or short sentence. No explanation is needed.

Example: "State the trend in first ionisation energy across Period 3." Good answer: "First ionisation energy generally increases across Period 3."

Describe

Describe means say what happens — report observations, trends, or features. You do not need to explain why.

Example: "Describe what you would observe when chlorine water is added to potassium bromide solution." Good answer: "The solution changes from colourless to orange/brown as bromine is displaced."

Explain

Explain means say what happens AND why. This is the most commonly misunderstood command word. Many students describe when asked to explain, losing half the available marks.