MEPX
Chapter 6 of 10All chapters
  1. 1Atoms
  2. 2The periodic table
  3. 3Bonding
  4. 4Reactions
  5. 5Acids and bases
  6. 6States of matter
  7. 7Mixtures and separation
  8. 8Organic chemistry
  9. 9Chemistry around you
  10. 10Working safely

Chapter 6 of 10

States of matter

Same particles, different arrangement.

Solid, liquid, gas

The particles are identical in all three; what changes is how much energy they have and how tightly they are held. Melting and boiling are changes of arrangement, not of substance.

  • Water expands when it freezes, which is unusual and why ice floats.
  • Sublimation goes straight from solid to gas, as with dry ice.

Gases

Pressure, volume and temperature are linked: heat a fixed volume and pressure rises. That relationship runs engines, weather and every aerosol can warning label.