Starters and Plenaries That Work for States of Matter (IB MYP)

States of matter is taught early in MYP Year 1 and then assumed for the next four years. That assumption is where the trouble starts: students carry particle diagrams that are wrong in specific, predictable ways, and nobody checks because the topic is considered done. Short openers and closers are the cheapest diagnostic instrument you have. Below are six, three to open and three to close, none longer than five minutes, each with what it actually tells you.

Three starters, and what each one diagnoses

Draw the same substance three times. One minute, three boxes, solid, liquid and gas, same substance. Collect nothing, just walk the room. You are looking for one error: students who draw fewer particles in the gas box. That single observation tells you whether the class believes matter is conserved during a change of state, and it is a more useful piece of information than any written test on the topic.

True, false or it depends. Five statements on the board. Gases have no mass. Liquids take the shape of their container. Particles expand when heated. Ice is colder than water. Steam is invisible. Students hold up one of three cards. The "it depends" option is what makes this worth doing, because it forces the class to attend to conditions rather than memorised sentences.

The odd one out. Three items, no correct answer: melting, evaporation, condensation. Students must justify any choice. It rehearses the vocabulary while requiring a relationship between the terms rather than a definition.

These run best from a bank you are not rebuilding weekly. The starter slides and short tasks in Chemistry Complete – Ready-to-Use Curriculum for Middle School Chemistry are editable, which matters here because a good starter is usually an existing one with the numbers changed.

Three plenaries that are not just recapping

The prediction you will check next lesson. Students write one prediction about the next practical and seal it in their book. Opening it at the start of the following lesson connects two lessons into a sequence and gives you a free retrieval event. It also makes being wrong routine rather than embarrassing.

Explain it to a Year 3 pupil. Two sentences, no technical vocabulary permitted. Students who cannot do this have the words and not the model, and the ban on jargon exposes that in about forty seconds.

One question you still cannot answer. Collected on slips. This is the one that changes your planning most often, and the questions are frequently better than the ones on your scheme: why does a hot drink stop steaming before it goes cold, why can you smell food from another room, why does a bag of crisps puff up on a plane.

Building the diagnostic into the unit rather than beside it

Six routines is enough for a whole unit if you rotate them. Use the drawing starter twice, at the beginning and again after the practical work, and compare. That comparison is assessable evidence against criterion A without setting a test, and it takes two minutes of lesson time each way.

Keep the particle model itself under pressure all the way through. Students accept the model as description rather than explanation unless you repeatedly ask what it predicts. Applications where particle behaviour has visible consequences are the best pressure, and a context like colour and dissolution gives you that: the sequence in Chemistry of Dyes – Structure, Color & Molecular Properties connects molecular structure to something students can see happening, which is a strong closing stimulus even when the full chemistry sits above MYP level.

Linking the topic to a global context that earns its place

States of matter is an easy topic to teach in a vacuum. A global context of globalisation and sustainability gives the particle model something to do: phase changes drive weather, ice loss and heat storage, and a plenary asking students to explain a real change using the model they drew that morning is a genuine transfer task.

Real datasets sharpen that considerably, because students have to read a change of state out of numbers rather than out of a diagram. Climate Change Data Lab – Understanding Climate Change Through Real Data gives you the tables and structured questions to run as a five-minute closer, which is enough to make the statement of inquiry mean something without turning a chemistry unit into a geography one.

What five minutes twice a lesson buys you

Across a six-week unit, that is roughly two hours of retrieval and diagnosis that cost no additional lessons. More importantly, you find the conserved-mass error in week one rather than in Year 4, when a student is trying to explain gas pressure and the underlying model quietly fails. The unit is working when a student, asked to draw a gas, stops halfway and counts back to check they have drawn the same number of particles as before.

Related reading from the Teacher Hub

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