internal energy + changes of state

• internal energy is total energy stores by particles in a system
• particles in a system vibrate or move around so have kinetic energy
• particles have energy in their potential energy stores due to their positions
• heating a system transfers energy to particles(in kinetic energy store) allowing them to move faster increasing internal energy
• heating the system leads to an increase in temperature or a change in state . if the temperature changes , the size of change depends on its mass, specific heat capacity and energy imput
• a change in state occurs if a system is heated enough to break the bonds of particles holding the particles together
• when a solid melts into liquid, it absorbs energy (latent heat)
• heating a liquid causes it to evaporate
• state can change due to cooling as particles lose energy and form bonds