A beaker of water is heated on a hob. The temperature of the water stays at 100 ∘C100\ ^\circ\text{C}100 ∘C while the water boils. What happens to the internal energy of the water while it boils?
It increases, because energy is still being transferred to the water
It stays the same, because the temperature of the water is constant
It decreases, because energy is carried away by the escaping steam
It stays the same, because the water is losing mass as it boils
40 exam-style questions on AQA GCSE Physics 3.2 Internal energy and energy transfers, covering 3.2.1 Internal energy, 3.2.2 Temperature changes in a system and specific heat capacity, and 3.2.3 Changes of state and specific latent heat. Each one has a worked solution and a mark scheme showing where the marks go.