internal energy and changes of state

Question 1

what is internal energy?

Answer 1

the total energy that particles in a substance have in their kinetic or potential energy stores

Question 2

how does heating increase internal energy?

Answer 2

•heating the system transfers energy to it’s particles (they gain energy in their kinetic stores and move faster) increasing internal energy
•this leads to a change in temperature or change in state.If the temperature changes the size of the change depends on the mass of the substance, it’s specific heat capacity and the energy input