Temperature and Heat

  • The amount of heat required for a given increase in temperature in a given substance is its specific heat.
  • Base unit is the calorie, one calorie is the amount of heat that will raise the temperature of one gram of water one degree Celsius
  • Heat is a form if kinetic energy as applied to molecules. Moving molecules create a raise in temperature, but the bonds hold them steady. The bonds have to be broken by heat to generate a raise in temperature. This is inefficient, and creates a stable temperature for organisms.



  • Transition to a solid
  • Density of water increases until it drops to four degrees Celsius
  • All molecules form hydrogen bonds immediately and expand.
  • For solid water to become liquid, 79.7 calories per gram are needed. This is its heat of fusion, and is drawn from the surroundings.
  • Presence of dissolved substance lowers temperature at which water freezes.