Heat is really important when it comes to melting and freezing things. Let’s break it down:

1. Melting:

   • When a solid heats up, it gets warmer.
   • Once it reaches a certain temperature, called the melting point, the heat helps break the bonds between the particles in the solid. This change turns the solid into a liquid.
   • For example, ice melts when it gets to 0°C. It needs 334 joules of heat for every gram to melt completely.

2. Freezing:

   • When a liquid cools down, it loses heat and gets colder.
   • At the freezing point, this loss of heat lets particles come together again, turning the liquid back into a solid.
   • Just like melting, water freezes at 0°C and gives off the same 334 joules of heat for every gram.

These changes show us just how important heat is in moving between solid and liquid states.