Thermal Energy (Heat) Temperature (°C) Notes: Thermal Energy and Phase Changes

Thermal Energy Temperature (°C) Adding Thermal Energy to H 2 0 Ice

Thermal Energy Temperature (°C) Adding Thermal Energy to H 2 0 Melting Ice

Thermal Energy Temperature (°C) Adding Thermal Energy to H 2 0 Melting Ice Water

Thermal Energy Temperature (°C) Adding Thermal Energy to H 2 0 Melting Ice Water Vaporization

Adding Thermal Energy to H Thermal Energy Temperature (°C) Melting Ice Water Vapor Vaporization

Thermal Energy Temperature (°C) Taking Thermal Energy from H 2 0 Vapor

Thermal Energy Temperature (°C) Taking Thermal Energy from H 2 0 Vapor Condensation

Thermal Energy Temperature (°C) Taking Thermal Energy from H 2 0 Water Vapor Condensation

Thermal Energy Temperature (°C) Taking Thermal Energy from H 2 0 Freezing Water Vapor Condensation

Thermal Energy Temperature (°C) Taking Thermal Energy from H 2 0 Freezing Ice Water Vapor Condensation

Thermal Energy Temperature (°C) Thermal Energy and Phase Changes Freezing Liquid Gas Condensation Melting Solid Vaporization

Rules of Thumb 1) Horizontal lines are phase changes 2) Diagonal lines are changes in temperature 3) Adding heat causes different phase changes than removing it!

VAPORIZATION (Liquid-Gas) evaporation – a change in phase from liquid to gas at the surface. – this cools the remaining liquid! boiling – a change in phase from liquid to gas below the surface. – this cools the remaining liquid! boiling point – the temperature that an object vaporizes or condenses.

Condensation (Gas  Liquid) this is a warming process for the liquid. gas molecules strike surface of liquid and give up so much energy that they can’t stay in gaseous phase examples droplets forming on mirror droplets on glass of water

Phase Change Process (S & L) melting – thermal energy is used to break bonds – the bonds that hold molecules in vibrating lattice structure are breaking. – the intermolecular forces lessen freezing – thermal energy is used to create bonds and hold molecules in place – the bonds that will hold molecules in position are forming – the intermolecular forces increase – melting point – the temperature at which an object either melts or freezes.