Question

why does an increase in temperature change the solid substance into the liquid state​

Answer 1

Heat is probably the easiest energy you can use to change the physical state the atom in a liquid have more energy than the atom in solid there is a special temperature for any substance called the melting point .... for example ice cube is in solid state when we heat that it would change into liquid state

Answer 2

Answer

a solid change to liquid on heating when we heat a solid then and the the heat energy changes to kinetic energy of particles of solid they start vibrating on a a faster rate due to heat energy the secondary bonds between the particles break down. after that the particles start separating away a due to which the fluidity increase the state of particle start changing. so on on heating the solid changes to liquid.

thank you

hope it helps you