Which of the following properties remain(s) the same when a solid melts to become liquid?

When heat is supplied to a crystalline solid, its temperature increases and hence, kinetic energy of the constituent particles increases. Due to increase in kinetic energy, the particles start vibrating with greater speed. As the temperature is further increased, the energy supplied in the form of heat overcomes the forces of attraction between the particles. At this stage, the particles leave their fixed position and start melting to become liquid. Once the solid starts melting, the temperature of the substance does not rise during the change of state. This is because the heat being supplied is used up in overcoming the forces of attraction between the particles of a solid during the change of state from solid to liquid. Therefore, temperature of the substance remains the same when solid melts to become liquid. The heat is believed to be hidden within the particles and is called latent heat.