Question

Particles of matter of water at 273 k have more energy as compared to particles of ice at same temparature . Why ?

Answer 1

When heat energy is supplied to ice it changes into water and then to vapor. If we cool the steam it gets converted into water and further cooling of water changes into ice.
Here the heat energy is used up in changing the state of matter. the heat is used to increase the kinetic energy of the particles of ice to such an extent that they break away from the rigid lattice structure of the solid form, ice, and move around freely to form the liquid form, water. So, until all the ice has melted, the heat absorbed does not raise the temperature of the ice-water mixture. This heat, which does not raise the temperature of the body, is called Latent Heat.