heating and cooling graphs

• Heating graph


  A graph showing the temperature of a substance increasing as it is gradually heated
• Heating a solid substance

  1. Temperature rises

  2. Temperature stops rising, becomes horizontal

  3. Solid changes state to liquid (melts)

  4. Temperature starts rising again
• Latent heat


  The energy needed for a substance to change state
• Melting point


  The temperature at which a solid changes state to a liquid
• Heating a liquid substance

  1. Temperature rises

  2. Temperature stops increasing, becomes horizontal

  3. Liquid changes state to gas (boils)

  4. Temperature starts rising again
• Boiling point


  The temperature at which a liquid changes state to a gas
• Cooling a gas substance

  1. Temperature decreases

  2. Temperature stops decreasing, becomes horizontal

  3. Gas changes state to liquid (condenses)

  4. Liquid changes state to solid (freezes)

  5. Temperature starts decreasing again