IGCSE›Edexcel IGCSE Physics›Mind mapsChanges of StateEdexcel IGCSE Physics: Mind mapStudy pack PDFAlso for this subtopic:Revision notesFlashcardsSubtopic testCover factsHeatingEnergy raises internal energy of particlesEither raises temperature or changes stateDuring a change of state temperature stays constantEnergy breaks or forms bonds between particlesChangesMelting: solid to liquid at fixed melting pointBoiling: liquid to gas throughout, fixed temperatureEvaporation: liquid to gas at the surfaceEvaporation occurs below the boiling pointParticlesSolid: regular, close, vibrate in fixed positionsLiquid: random, close, slide past each otherGas: random, far apart, move freely at speedState changesheat and energyJkg°CSpecific heatEnergy to raise 1 kg by 1 °CUnit is J/kg °CΔQ=mcΔT\Delta Q = mc\Delta TΔQ=mcΔT2 kg water, 20 °C rise → 168 000 JGraphsTemperature-time graph has a flat sectionFlat = melting or boilingEnergy is still being suppliedExam tipsDescribe both spacing and motionExaminers credit each separately