Read the command word first

Every year, students lose marks on questions they understood, because they answered a different question from the one asked. The command word, usually the first word of the question, tells you what the examiner wants.

State means give the fact. Writing more won't help, and adding something wrong can cancel a mark you had already earned.

Describe means say what happens. If there's data, use it: write "it increases from 20 °C to 45 °C", not just "it increases".

Explain means say why. If your answer has no "because" in it, stated or implied, it's probably incomplete.

Suggest means apply what you know to an unfamiliar situation. More than one answer may earn credit.

Take the same topic asked two ways. State the effect of temperature on the rate of reaction needs only "the rate increases". Explain the effect of temperature on the rate of reaction needs the reason: the particles move faster, so they collide more often, and more of those collisions have enough energy to react. The science is the same. Only the second question asks for the reasoning.

Before you write, find the command word and decide what kind of answer it needs. It takes five seconds, and it saves more marks than almost anything else.