How Materials Change State
CONCEPTUALExplain melting, freezing, boiling, condensing, and sublimation using the particle model, interpreting heating and cooling curves to identify melting and boiling points
Mastery Evidence
- Describes what happens to particles during each change of state
- Reads a heating/cooling curve and identifies the melting point and boiling point from the flat regions
- Explains why temperature stays constant during a change of state
- Distinguishes between evaporation (from surface, any temperature) and boiling (throughout liquid, at boiling point)
Assessment Prompt
“If [child] was heating a block of ice in a pan and drew a graph of temperature over time, could they explain why the line goes flat at certain points — and what's happening to the particles when it does?”
Curriculum Standards2 alignments
KS3.Sci.Chem.PNM.2The national curriculum in Englandchanges of state in terms of the particle model
KS3.Sci.Chem.PNM.4The national curriculum in Englandthe differences in arrangements, in motion and in closeness of particles explaining change of state, shape and density, the anomalous expansion of water, and the differences in the compressibility of solids, liquids and gases
Prerequisites3
- The Particle ModelhardAges 11—12
- Drawing Particle DiagramssoftAges 7—11
- Heating & Cooling ChangeshardAges 7—9
Show full prerequisite tree
- The Particle Model hard
Changes of state are explained using the particle model — the particle model must be understood first
- Drawing Particle Diagrams hard
Using the particle model to explain density, compressibility, and anomalous expansion requires fluent reading and drawing of particle diagrams
- Matter Is Made of Particles hard
KS3 particle model extends US KS2 introduction to matter as particles too small to see
- Drawing Particle Diagrams hard
Developing a model of matter as particles too small to see is built on the particle diagram representation
- Heating & Cooling Changes hard
Must observe state changes before explaining them with particle model
- States of Matter Vocabulary hard
Describing and measuring changes of state requires solid/liquid/gas vocabulary and the term 'change of state'
- Drawing Particle Diagrams hard
Observing and describing change of state requires reading particle diagrams showing how arrangement changes on heating or cooling
- Solids, Liquids & Gases hard
Must understand observable states of matter before modelling them with particles
- States of Matter Vocabulary hard
Comparing and grouping materials as solids, liquids, or gases requires the naming vocabulary for the three states
- Drawing Particle Diagrams hard
Comparing and grouping solids, liquids, and gases by properties is greatly aided by the particle diagram representation
- Heating & Cooling Changes hard
Must classify states of matter before understanding changes between states
- States of Matter Vocabulary hard
Describing and measuring changes of state requires solid/liquid/gas vocabulary and the term 'change of state'
- Drawing Particle Diagrams hard
Observing and describing change of state requires reading particle diagrams showing how arrangement changes on heating or cooling
- Grouping Materials hard
Must group materials by properties before classifying into three states of matter
- States of Matter Vocabulary soft
Describing physical properties of materials uses solid/liquid/gas vocabulary introduced in the states of matter LANGUAGE node
- Changing Shapes of Solids soft
Changing shapes of solids provides context for understanding solid properties
- Describing Material Properties hard
Must know material properties before investigating how shapes change
- States of Matter Vocabulary soft
Describing physical properties of materials uses solid/liquid/gas vocabulary introduced in the states of matter LANGUAGE node
- Solids, Liquids & Gases hard
KS3 particle model extends KS2 classification of solids, liquids and gases by observable properties
- States of Matter Vocabulary hard
Comparing and grouping materials as solids, liquids, or gases requires the naming vocabulary for the three states
- Drawing Particle Diagrams hard
Comparing and grouping solids, liquids, and gases by properties is greatly aided by the particle diagram representation
- Heating & Cooling Changes hard
Must classify states of matter before understanding changes between states
- States of Matter Vocabulary hard
Describing and measuring changes of state requires solid/liquid/gas vocabulary and the term 'change of state'
- Drawing Particle Diagrams hard
Observing and describing change of state requires reading particle diagrams showing how arrangement changes on heating or cooling
- Grouping Materials hard
Must group materials by properties before classifying into three states of matter
- States of Matter Vocabulary soft
Describing physical properties of materials uses solid/liquid/gas vocabulary introduced in the states of matter LANGUAGE node
- Changing Shapes of Solids soft
Changing shapes of solids provides context for understanding solid properties
- Describing Material Properties hard
Must know material properties before investigating how shapes change
- States of Matter Vocabulary soft
Describing physical properties of materials uses solid/liquid/gas vocabulary introduced in the states of matter LANGUAGE node
- Drawing Particle Diagrams soft
Explaining changes of state using the particle model draws on particle diagram literacy
- Heating & Cooling Changes hard
KS3 heating/cooling curves and particle-level explanation extends KS2 observation that materials change state at specific temperatures
- States of Matter Vocabulary hard
Describing and measuring changes of state requires solid/liquid/gas vocabulary and the term 'change of state'
- Drawing Particle Diagrams hard
Observing and describing change of state requires reading particle diagrams showing how arrangement changes on heating or cooling
Unlocks1
- Reactions That Release or Absorb HeatsoftAges 12—13