Answers to AQA GCSE Internal Energy

Practice Questions

1.Define the term internal energy

Internal energy is the total energy stored inside the system by the particles

2. Explain why internal energy increases when water is heated from 20ºC to 50ºC

As the temperature of the water increases, the kinetic energy of the particles increases. Internal energy depends on kinetic energy, so if kinetic energy increases, so does internal energy

3. Explain why internal energy increases when a solid is melting.

During melting, if heat energy is still being supplied, the energy supplied is increasing the potential store of the particles. Internal energy depends on the potential store, so if the potential store increases, so does the internal energy