The key to answer this question is the forces of attraction between the particles and the heat required to overcome these.
During a change of state, the temperature remains constant. This is because all the heat supplied to increase the temperature is utilised in changing the state by overcoming the forces of attraction between the particles. This heat is called the latent heat. Latent heat does not contribute in increasing the temperature of the substance. So, the temperature of any substance remains constant during the change of state.