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Physics Paper 1 · P3 · Lesson 3.5

Changes of state

Name the changes and explain why no material is lost.

Key ideas1 of 4

Ice and water are the same substance

Melting is solid → liquid. Freezing reverses it. These are physical changes: no new substance forms. Water can freeze back to ice and recover its solid properties.

A single ice cube resting in a puddle of meltwater on a reflective surface.

Both the ice and liquid are water.

Next: Internal energy and temperature →
Topic resources and sources

Daily 5 · Exam practice · A4 revision sheet

All P3 content here is shared by Foundation and Higher Tier. Stretch questions combine the core ideas; they are not additional Higher Tier-only content.

AQA Combined Science Trilogy specification · 6.3.1.2. Original notes, questions and diagrams. Particle diagrams are simplified; animation speeds and experimental numbers are illustrative.

Photographs: Melt by Kathy Jantz, CC BY 4.0; Menisco 18mL-2 by Leandro Maranghetti Lourenço, CC BY-SA 3.0 (chosen from the licences offered); Bicycle Pump foot operated by Scott Ehardt (SCEhardt), Public domain, released worldwide by copyright holder. Images displayed without cropping or alteration; a resized source image is used for the ice.