Latent heat When the molecules of a substance settle into the regular pattern of a solid, energy is released as bonds are formed. This energy released is called latent heat. This stops the temperature from falling. Energy released (“latent” = “hidden”)
Latent heat The opposite happens when a solid melts. Heat is needed to break the bonds between the solid particles (instead of raising the temperature) Temp (°C) Time (mins) Melting point solid liquid Energy absorbed
Melting ice Heat energy is needed for converting ice at 0 º C to water at 0 º C This heat energy is needed to melt the ice, NOT make it hotter 0°C
Freezing water Heat energy is released when water at 0 º C is converted to ice at 0 º C This heat is keeps the temperature constant whilst the water is freezing. 0°C
Evaporating water Heat energy is absorbed by the water when changing to a gas, keeping the temperature constant. 100°C
Got it? Can you stick the summary sheet into your book?