Science // Matter & Materials

States of Matter Vocabulary

Name and distinguish the three states of matter — solid, liquid, and gas — using properties vocabulary: hard, rigid, runny, flows, keeps its shape, fills its container; use 'change of state' to describe what happens when materials are heated or cooled

Ages
5 to 7
Type
Language
Builds on
0 topics
Leads to
3 topics

Quick check

If you point to water, ice, and steam from a kettle, can the learner correctly call each one a liquid, solid, or gas — and use those words naturally?

Ask this to see whether the topic is secure.

Topic // Mastery

What mastery looks like

What a learner can do once this topic is secure.
  • Correctly sort a set of everyday materials as solid, liquid, or gas and give a reason for each
  • Use the terms solid, liquid, and gas accurately when describing everyday substances
  • Use 'change of state' to describe what happens when ice melts or water boils

Topic // Map

Where this fits

What to learn first and what this topic opens up, with the reason for each link. Required links come first.
  • RequiredMust come first
  • HelpfulHelps, but not essential

Before this

0 topics

Nothing in the catalogue comes before this topic, so it is a good place to start.

You are here

States of Matter Vocabulary

Ages 5 to 7 // Language

Leads to

3 topics
  • Heating & Cooling ChangesRequired

    Matter & Materials // Ages 7 to 9

    Describing and measuring changes of state requires solid/liquid/gas vocabulary and the term 'change of state'

  • Solids, Liquids & GasesRequired

    Matter & Materials // Ages 8 to 9

    Comparing and grouping materials as solids, liquids, or gases requires the naming vocabulary for the three states

  • Describing Material PropertiesHelpful

    Matter & Materials // Ages 5 to 6

    Describing physical properties of materials uses solid/liquid/gas vocabulary introduced in the states of matter LANGUAGE node

Topic // Research-informed

Teaching notes

From the Marble Skill Taxonomy. These notes have not been validated in classrooms, so treat them as a starting point for your own judgement.

The approach

Early (ages 5–7) informal vocabulary-building for the three states of matter — solid, liquid, gas — anchored to OBSERVABLE BEHAVIOUR rather than abstract definitions: a solid keeps its shape, a liquid flows and takes the shape of its container (forms a pool not a pile), a gas spreads out to fill whatever holds it. Water is the through-line (ice, water, steam) so one familiar material carries all three words plus 'change of state'. It deliberately makes an invisible gas tangible (air in a balloon) to begin unseating 'gas is not stuff'. This seeds the later UK Year 4 objective; at this age there is no KS1 statutory states content, and NGSS has no performance expectation dedicated to naming the three states. (Steam, meaning water vapour, is the gas state and is invisible; the white cloud seen above a kettle is tiny drops of liquid water that form as the steam cools, so it should not be presented as the gas.)

Common misconceptions

  • Gases are not matter / are weightless — rooted in 'seeing is believing' since most gases are invisible (a very common and persistent idea).
  • A 'solid' must be hard and rigid, so powders and sand (which pour) get miscalled liquids.
  • Thinking of a liquid as anything that pours, conflating flow with the liquid state.
  • The everyday meaning of 'gas' (fuel) crowding out the physical-state meaning.
  • Treating steam/water vapour as something other than water, or as 'hot air', rather than water in its gas state.

Useful representations

  • Water shown in three states (ice cube, glass of water, steam) as the anchor example
  • Behaviour cards: 'keeps its shape' / 'flows, takes the shape of its container' / 'spreads to fill the space'
  • A three-bin sort (solid / liquid / gas) of everyday substances
  • A balloon or bubbles to make an invisible gas tangible
  • A simple melt/boil before-after pair introducing 'change of state'

Teaching practices

  • Define each state by observable behaviour ('keeps its shape' / 'forms a pool not a pile' / 'fills its container'), not abstract definitions.
  • Use water as the through-line — ice, water, steam — so one familiar material demonstrates all three states and the change-of-state word.
  • Sort many real examples and talk through tricky cases (sand, powder, honey) to test the behaviour rule rather than surface looks.
  • Introduce a felt-but-unseen gas (air in a balloon, bubbles) early to begin challenging 'gas is not stuff'.
  • Handle everyday 'gas' language carefully — clarify the science sense versus natural gas/petrol so the word doesn't mislead.
  • Keep 'change of state' concrete and reversible (melting/freezing water) at this age; avoid heating that causes burning/cooking (a chemical change).

Activities to try

  1. 1

    Tap-to-name the three states in a kitchen scene

    Why it works: Three new category words attach to familiar things through how they behave (shape and container), and the SAME water can be solid, liquid or gas (the gas, steam or water vapour, is invisible), with 'change of state' naming the move between them; a gas (air) really is stuff that spreads out to fill its container.

    1. Explore a home/kitchen scene and tap everyday items to hear each one's state and the behaviour reason, e.g. tap the ice cube → 'SOLID — it keeps its shape'; tap the juice → 'LIQUID — it flows and takes the shape of the cup'; tap the kettle → 'When water boils it becomes steam, a GAS you can't see — it spreads out into the air. The white cloud is tiny water drops made as the steam cools.'
    2. Visit a dedicated water trio panel showing the SAME water as hard ice, runny liquid, and invisible steam (water vapour) shown as spreading arrows or a dotted cue, with audio explaining that you can't see the gas itself.
    3. Open a 'melting' and a 'boiling' flap on the water panel to hear that the move between states is called a 'change of state'.
    4. Tap the balloon in the corner to hear 'the air inside is a GAS — it fills the balloon up'.
  2. 2

    Sort real substances into solid / liquid / gas bins

    Why it works: The defining test is BEHAVIOUR (keeps its shape / flows and takes its container's shape / spreads to fill the space), not surface looks, size, smell or wetness; tricky cases like pourable powders are still solids because each grain keeps its shape.

    1. Drag or place plentiful everyday substances into three bins labelled solid, liquid and gas.
    2. For a chosen item, trigger a short 'watch it behave' action — a liquid pouring and taking the shape of a cup, a solid holding its shape, a gas (shown with a coloured animation cue, since most gases are invisible) spreading to fill a jar — and check the sort against the behaviour.
    3. Discuss borderline cases out loud: Is sand a solid when it 'pours'? What about honey, sugar, salt, or a damp sponge?
    4. Use a mini melt/boil before-after pair to practise the words 'change of state'.
  3. 3

    Use the words like a scientist (checkpoint)

    Why it works: Correct, meaningful USE of the behaviour-vocabulary in context (including tricky cases) shows genuine understanding, not recitation of the three words.

    1. Name whether each of several things is solid, liquid or gas AND describe HOW it behaves: a rock, milk, the air in a balloon, and sand.
    2. Explain what 'change of state' means, using ice as the example (ice melting to water, or water freezing back), including what happens to ice on a warm day.
    3. Answer probing questions: Is the air in the balloon solid, liquid or gas — how can you tell it's really there? Sand pours like a drink — is sand a liquid? Look closely at one grain. Is toothpaste a solid or a liquid — what makes it hard to decide?

Science // Matter & Materials

More in Matter & Materials

All 40 topics